JP2012176654A - Communication control device and in-vehicle system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flexibly change allocation of radio communication bands in response to changes of the radiocommunication bands or vehicle states in an in-vehicle system.SOLUTION: A communication control device 110 holds a table for showing the allocation ratio of the radio communication bands allocated to each data transmitter for each of combinations of the vehicle states and level of the radio communication bands, determines the running state of the vehicle based on the vehicle running information input from an electronic control device 150, refers to the table based on the determined running state and effective bands of the entire in-vehicle system transmitted from the radio communication device 111, determines the radio communication bands allocated to each data transmitter, and transmits the determined radio communication bands to each data transmitter. In response to the changes of the radiocommunication bands or changes of the vehicle states, the allocation of the radiocommunication bands can be flexibly changed.

Description

  The present invention relates to a communication control device mounted on a vehicle together with a plurality of data transmission devices that transmit data.

In recent years, in-vehicle systems centering on car navigation systems tend to increase the number of communication terminals per vehicle, as represented by the spread of rear monitoring systems and rear seat monitors.
However, since the bandwidth used for communication is limited, Patent Literature 1 and Patent Literature 2 disclose a method for controlling the transmission bandwidth assigned to each video data according to the driving situation and the surrounding situation.

  On the other hand, the increase in the number of communication terminals per vehicle as described above and the digitization of in-vehicle equipment increase the number and total weight of communication cables, leading to an increase in production costs and a deterioration in fuel efficiency. Yes. In order to solve this problem, wireless data communication in a vehicle is about to be put into practical use.

JP 2002-135758 A JP 2005-222307 A

The techniques of Patent Document 1 and Patent Document 2 can sufficiently cope with a network having a constant transmission band such as wired communication, but for a network where the transmission band changes momentarily such as wireless communication, However, there is a problem that information that requires immediacy cannot be provided in real time or information with sufficient accuracy may not be provided.
In addition, data that is important for the passenger changes when the driving state of the vehicle or the state of the surrounding environment of the vehicle changes.

  The present invention has been made in view of such circumstances, and it is a main object of the present invention to flexibly change the allocation of radio communication bands in response to changes in radio communication bands and vehicle conditions.

The communication control device according to the present invention is:
A plurality of data transmission devices that wirelessly transmit data, and a communication control device that is mounted on a vehicle together with a data reception device that wirelessly receives data from each data transmission device and measures a wireless communication band at the time of data reception Because
A state determination unit for determining the state of the vehicle;
Communication for determining a wireless communication band to be assigned for each data transmission device based on the state of the vehicle determined by the state determination unit, the attribute of each data transmission device, and the wireless communication bandwidth measured by the data reception device A bandwidth determination unit;
And a communication band notification unit for notifying each data transmission device of the wireless communication band determined by the communication band determination unit.

  According to the present invention, since the wireless communication band to be assigned is determined for each data transmission device based on the state of the vehicle, the attribute of each data transmission device, and the measured wireless communication bandwidth, The allocation of the radio communication band can be flexibly changed in response to the change of

1 is a diagram illustrating a configuration example of an in-vehicle system according to Embodiment 1. FIG. FIG. 4 is a diagram showing an example of a bandwidth allocation table according to the first embodiment. FIG. 3 is a flowchart showing an operation example of each terminal according to the first embodiment. FIG. 4 is a diagram illustrating a configuration example of an in-vehicle system according to a second embodiment. FIG. 10 is a diagram showing an example of a bandwidth allocation table according to the second embodiment. FIG. 2 is a diagram illustrating a configuration example of a communication control apparatus according to the first embodiment. FIG. 3 is a flowchart showing an operation example of the communication control apparatus according to the first embodiment. FIG. 4 is a diagram illustrating a configuration example of a communication control apparatus according to a second embodiment. FIG. 6 is a flowchart showing an operation example of the communication control apparatus according to the second embodiment. FIG. 3 is a diagram illustrating a hardware configuration example of a communication control apparatus according to the first and second embodiments.

Embodiment 1 FIG.
FIG. 1 is a block diagram illustrating a configuration example of an in-vehicle system according to the present embodiment.
The communication control device 110 manages the communication of the entire network and assigns a wireless communication band to each terminal.
The term “terminal” is a generic term for an imaging device 120, an imaging device 130, a playback device 140, and a broadcast receiving device 160, which will be described later.
The wireless communication device 111 performs wireless communication with other wireless communication devices in the vehicle.
The imaging device 120 is a camera that captures the front of the vehicle.
The wireless communication device 121 performs wireless communication with other wireless communication devices in the vehicle.
The imaging device 130 is a camera that captures the rear of the vehicle.
The wireless communication device 131 performs wireless communication with other wireless communication devices in the vehicle.
The playback device 140 includes a disk drive such as Blu-ray (registered trademark) or DVD.
The wireless communication device 141 performs wireless communication with other wireless communication devices in the vehicle.
The broadcast receiving device 160 includes an antenna that receives broadcast radio waves and a tuner.
The wireless communication device 161 performs wireless communication with other wireless communication devices in the vehicle.
The display device 170 is disposed on the front seat side and displays video information, a map, a guidance screen, and the like.
The display device 180 is disposed on the rear seat side and mainly displays video information.
The wireless communication device 181 performs wireless communication with other wireless communication devices in the vehicle.

The electronic control unit 150 performs control necessary for vehicle travel, such as gear control, steering wheel control, accelerator control, and brake control.
In addition, the electronic control device 150 outputs travel information, which is information related to the traveling direction (forward / reverse) and travel speed of the vehicle, to the communication control device 110.

The display device 170 transmits video data and audio data transmitted from the imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 through the wireless communication devices 121, 131, 141, and 161, respectively, through the wireless communication device 111. Receive, display, and output audio.
There are cases where one of the four videos is selected for display and another is selected for display simultaneously.
In some cases, only the map screen and the guidance screen are displayed, and the video information is not displayed.
Further, only audio data may be output.

The display device 180 receives video data transmitted from the imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 through the wireless communication devices 121, 131, 141, and 161, respectively, through the wireless communication device 181. Display and audio output.
There are cases where one of the four videos is selected for display and another is selected for display simultaneously.
In some cases, only the map screen and the guidance screen are displayed, and the video information is not displayed.
Further, only audio data may be output.

  The wireless communication device 111 calculates the current effective communication band from the error rate of the wireless signal transmitted from each terminal, and outputs the total value to the communication control device 110.

As described above, the imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 transmit video data and audio data through the wireless communication devices 121, 131, 141, and 161, respectively. The combination of the communication device 121, the combination of the imaging device 130 and the wireless communication device 131, the combination of the playback device 140 and the wireless communication device 141, and the combination of the broadcast receiving device 160 and the wireless communication device 161 are respectively the data transmission devices. It is an example.
Hereinafter, when there is no need to distinguish each combination, the combination of these combinations is referred to as a data transmission device.
The imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 are collectively referred to as a terminal.

The display device 170 receives data from the data transmission device via the wireless communication device 111, and the display device 180 receives data from the data transmission device via the wireless communication device 181. The combination with the wireless communication device 111 and the combination of the display device 180 and the wireless communication device 181 are examples of data receiving devices.
Hereinafter, when there is no need to distinguish each combination, the combination of these combinations is referred to as a data receiving device.
As described above, the imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 are also collectively referred to as a terminal.

For example, after the in-vehicle system 100 is activated, the communication control device 110 transmits information of a bandwidth allocation table that defines the wireless communication allocated bandwidth of each terminal through the wireless communication device 111.
The imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 control the generated code amount based on the information in the band allocation table.
The generated code amount is controlled by changing any one or a plurality of encoding parameters such as a frame size, a frame rate, and a quantization value.
As will be described later, the communication control device 110 notifies the changed wireless communication band every time it decides to change the wireless communication band assigned to each terminal without transmitting the information of the entire bandwidth allocation table. Information may be transmitted.

  FIG. 2 shows an example of the bandwidth allocation table in the first embodiment.

In the bandwidth allocation table, a plurality of states related to the traveling of the vehicle are indicated as driving situations, and a plurality of stages of wireless communication bandwidth levels (20 Mbps, 16 Mbps, 12 Mbps, and 8 Mbps in the example of FIG. 2) are indicated as effective bandwidths.
Then, sub-tables Table 1-1 to Table 4-4 are provided that indicate the allocation ratios of the radio communication bands allocated to the respective data transmission apparatuses for each combination of the driving situation and the effective band.
As described above, the effective band is the total value of the wireless communication bands measured when the wireless communication apparatus 111 receives data from each data transmission apparatus.
In each sub-table, for each driving situation, a higher allocation ratio is set for a data transmission device that transmits data that is presumed to be important for a passenger of the vehicle when the vehicle is in the driving situation.
Specifically, during stoppage, more bands are allocated to entertainment-type terminals such as playback devices and broadcast receiving devices, and when the overall communication bandwidth is reduced, the overall bandwidth is reduced almost in proportion to it.
In normal driving, the bandwidth allocated to safety-type terminals such as the front camera and rear camera is increased compared to when the vehicle is stopped.
During acceleration, the bandwidth allocated to the front camera is increased, and the bandwidth allocated to the front camera is secured even if the overall effective communication bandwidth drops.
Conversely, during deceleration or back-drive, the bandwidth allocated to the rear camera is increased, and the bandwidth allocated to the rear camera is secured even if the overall effective communication bandwidth is reduced.
The bandwidth allocation table is an example of allocation ratio information.

The communication control device 110 corresponds to the sub-table group in FIG. 2 based on the information on the traveling direction and traveling speed obtained from the electronic control device 150 and the total effective communication bandwidth obtained from the wireless communication device 111. Select a subtable.
Further, when the subtable is changed, for example, the number of the subtable (Table1-1 or the like) is transmitted to each terminal through the wireless communication device 111 as the band notification information.
When the entire bandwidth allocation table is not transmitted to each terminal, the communication control device 110 may transmit the selected sub table itself to each terminal through the wireless communication device 111 as bandwidth notification information. .
If the entire bandwidth allocation table has not been transmitted to each terminal, the communication control apparatus 110 calculates an individual communication band for each terminal based on the selected sub-table as band notification information. The calculation result may be notified.
The wireless communication device 111 transmits, to each terminal, one of the sub-table number received from the communication control device 110, the wireless communication band for each terminal in the sub-table, and the calculated wireless communication band for each terminal.
In addition, the wireless communication device 111 transmits the effective communication band for each measured terminal (for each wireless communication device 121, 131, 141, 161) to each terminal.

  The imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 respectively transmit the subtable number transmitted from the wireless communication device 111 through the wireless communication devices 121, 131, 141, and 160, and each terminal in the subtable. Either the communication band or the calculated communication band for each terminal is received, and further, the effective communication band for each terminal is received.

The imaging device 120, the imaging device 130, the playback device 140, and the broadcast receiving device 160 control the amount of generated code so as to be within the allocated band described in the subtable as the subtable number is updated.
Also, the data transfer time is calculated from the effective communication bandwidth of each terminal and the capacity of the data waiting for transmission.
This transfer time is compared with a threshold value, and if the threshold value is exceeded, the sub-table number is changed locally, and encoding control is performed according to the changed allocated bandwidth.

  Next, a configuration example of the communication control apparatus 110 according to the present embodiment will be described with reference to FIG.

  In FIG. 6, an electronic control unit I / F (interface) unit 1106 inputs travel information, which is information related to the traveling direction (forward / backward) and travel speed, of the vehicle from the electronic control unit 150.

The state determination unit 1105 determines the state of the vehicle from the travel information input from the electronic control unit 150 by the electronic control unit I / F unit 1106.
For example, when the traveling speed indicated in the traveling information from the electronic control unit 150 is 0 Km / h, the state determination unit 1105 determines that the vehicle is stopped, and is indicated in the previous traveling information. If the amount of change between the traveling speed and the traveling speed indicated in the current traveling information is equal to or less than a predetermined threshold, it is determined that the vehicle is traveling normally.
In addition, if the travel speed indicated in the current travel information is faster than the travel speed indicated in the previous travel information and the amount of change exceeds a predetermined threshold, it is determined that the vehicle is accelerating. If the travel speed indicated in the travel information is slower than the travel speed indicated in the previous travel information and the change amount exceeds a predetermined threshold, it is determined that the vehicle is decelerating.
Further, if the traveling direction indicated by the traveling direction information from the electronic control unit 150 is reverse, it is determined that the vehicle is in the back operation.
Note that the method of state determination by the state determination unit 1105 is not limited to these.

  The information storage unit 1104 stores the bandwidth allocation table shown in FIG.

The communication band determination unit 1103 is based on the vehicle state determined by the state determination unit 1105, the attribute of each data transmission device, and the wireless communication band (total value of the effective communication band) measured by the wireless communication device 111. A radio communication band to be allocated is determined for each data transmission apparatus.
More specifically, in the sub-table group of the bandwidth allocation table of FIG. 2, the vehicle state determined by the state determination unit 1105 and the wireless communication band measured by the wireless communication device 111 (the total value of the effective communication bands) ) Is extracted, and a wireless communication band for each terminal is determined based on the extracted table.

  The communication band notification unit 1102 generates band notification information that notifies the communication band determined by the communication band determination unit 1103, transmits the band notification information from the wireless communication apparatus I / F unit 1101 to the wireless communication apparatus 111, and The communication device 111 notifies each data transmission device of the wireless communication band.

  The wireless communication apparatus I / F unit 1101 receives band information for notifying the effective band from the wireless communication apparatus 111 and transmits band notification information for notifying the band allocated to each data transmission apparatus to the wireless communication apparatus 111. .

  Next, an operation example of the communication control apparatus 110 according to the present embodiment will be described with reference to FIG.

First, the electronic control device I / F unit 1106 inputs travel information that is information related to the traveling direction (forward / reverse) and travel speed of the vehicle from the electronic control device 150, and outputs the input travel information to the state determination unit 1105. Then, the state determination unit 1105 determines the driving situation (the traveling state of the vehicle) based on the traveling information (S701).
Further, the state determination unit 1105 outputs the determination result to the communication band determination unit 1103.
Next, the wireless communication apparatus I / F unit 1101 receives band information for notifying the effective band from the wireless communication apparatus 111, outputs the received band information to the communication band determination unit 1103, and the communication band determination unit 1103 The execution bandwidth indicated in the information is confirmed (S702).
Note that the order of S701 and S702 may be switched.

The communication band determining unit 1103 stores the previous driving situation and the effective band, and the current driving situation (the state determined in S701) and the effective band (the effective band confirmed in S702) are the previous driving state and It is determined whether there is a change in the effective band (S703), and if there is no change in both the operating status and the effective band, the process is terminated, while if there is a change in at least one, the band of FIG. From the allocation table, a sub-table corresponding to the current operation status and effective bandwidth is extracted (S704).
When the current effective bandwidth is other than the value shown in the bandwidth allocation table of FIG. 2, for example, when the vehicle is currently “stopped” and the effective bandwidth is “18 Mbps”, the effective bandwidth “ Since it is equal to or greater than “16 Mbps” and less than “20 Mbps”, the sub-table Table1-2 is selected.

Next, the communication band determining unit 1103 determines a radio communication band to be allocated to each terminal based on the extracted subtable (S705).
For example, the bandwidth of each terminal indicated in the selected sub-table may be used as it is, or as described above, when the current effective bandwidth is other than the value indicated in the bandwidth allocation table of FIG. The bandwidth of each terminal may be calculated based on the difference between the actual effective bandwidth and the effective bandwidth of the selected sub-table.
As described above, when the effective bandwidth is “18 Mbps” and the sub-table Table1-2 is selected, for example, the following calculation is performed.
Front camera bandwidth: (18/16) × 1≈1.13 Mbps
Rear camera bandwidth: (18/16) × 1≈1.13 Mbps
Band of playback device: (18/16) × 7≈7.88 Mbps
Broadcast receiver bandwidth: (18/16) × 7≈7.88 Mbps
The calculation method is not limited to this.

Next, the communication band notification unit 1102 generates band notification information for notifying the communication band determined by the communication band determination unit 1103 (S706).
Each terminal holds all the sub-tables (Table 1-1 to Table 4-4) of the bandwidth allocation table of FIG. 2, and the allocated bandwidth of each terminal shown in the sub-table selected in S704 is used as it is. When used, the communication band notification unit 1102 generates band notification information for notifying the number of the subtable selected in S704 (Table 2-1 or the like).
Further, each terminal does not hold all the sub-tables (Table 1-1 to Table 4-4) of the bandwidth allocation table of FIG. 2, and the allocation of each terminal shown in the sub-table selected in S704 When the band is used as it is, the communication band notification unit 1102 generates band notification information that notifies the value of the allocated band of each terminal in the sub-table selected in S704.
Further, when the bandwidth calculated by the communication band determining unit 1103 is allocated to each terminal, band notification information for notifying the value of the allocated band of each terminal calculated by the communication band determining unit 1103 is generated.

  Finally, the communication band notification unit 1102 transmits the band notification information generated in S706 from the wireless communication apparatus I / F unit 1101 to the wireless communication apparatus 111, and transmits the band notification information from the wireless communication apparatus 111 to each data transmission apparatus. (S707).

Next, a method of controlling the amount of generated code based on the allocated bandwidth in each terminal that has been notified of the allocated bandwidth will be described with reference to FIG.
FIG. 3 is a flowchart of a process for controlling the amount of generated code executed in each terminal.
Note that FIG. 3 is based on the premise that each terminal previously holds all sub-tables of the bandwidth allocation table of FIG.

In S300, the terminal calculates the transfer time until the transmission of all the transmission waiting data is completed from the capacity of the transmission waiting data stored in the buffer and the effective communication band for each terminal.
In S301, the transfer completion time calculated in S300 is compared with a threshold value.
If the transmission completion time is less than or equal to the threshold, the process is completed without doing anything, but if the transmission completion time is greater than the threshold, the process proceeds to S302.
In S302, the terminal changes the sub-table to be used to a table number under a condition that the bandwidth is low.
In S303, the generated code amount is controlled so as to be the allocated band defined in the table changed in S302, and the process returns to S300.
That is, the encoding rate of newly generated data is set to a lower encoding rate than the encoding rate corresponding to the wireless communication band notified by the communication control apparatus 110.

  In addition, the threshold value referred by S301 may be transmitted to each terminal from the communication control apparatus 110 after starting the vehicle-mounted system 100, and each terminal may hold | maintain a fixed value beforehand.

  As described above, in the present embodiment, the communication control apparatus can change the transmission band allocation ratio according to the size of the transmission band. Therefore, the important video data determined by the driving situation of the vehicle is the transmission band. Even if fluctuates, it can be transmitted in real time while maintaining the required accuracy.

  Further, in this embodiment, each terminal calculates the transmission completion time of video data, and controls the amount of generated code when it exceeds the threshold set for each transmission band. Can be transmitted without stopping or delaying.

As described above, in the present embodiment,
An image pickup device that captures a state outside or inside the vehicle, a playback device that reads a video source from a medium, such as a DVD player or a Blu-ray (registered trademark) disk player, a broadcast receiver that receives broadcast radio waves, and video data are displayed. In an in-vehicle system composed of a display device, a wireless communication device that performs wireless communication in the vehicle, an electronic control device that controls the traveling content of the host vehicle, and a communication control device that controls a communication band between the terminals,
It has been explained that the communication control device can change the allocation ratio of the transmission band according to the size of the transmission band when allocating the communication band to each terminal according to the information obtained from the electronic control device.

In the present embodiment,
The communication control device calculates the transmission completion time of video data that each device terminal intends to transmit, performs coding control on the terminal whose transmission completion time exceeds a threshold, and suppresses the generated code amount Explained.

Embodiment 2. FIG.
FIG. 4 is a block diagram illustrating a configuration example of the in-vehicle system according to the present embodiment.
In FIG. 4, the same reference numerals are used for the same elements as in FIG.
Further, description of the same elements as those in FIG. 1 is omitted.
In FIG. 1, the communication control device 110 is connected to the electronic control device 150 and travel information is input from the electronic control device 150, but in FIG. 4, the communication control device 110 is connected to the sensors 450 to 452, and the sensor 450 Input sensor information from ~ 452.
Sensors 450 to 452 are sensors that monitor the surrounding environment of the vehicle.
For example, the sensor 450 includes a GPS (Global Positioning System), a direction sensor, a vehicle speed sensor, a map information storage device, and a determination device that determines a vehicle position and a traveling direction based on information obtained from these.
The sensor 451 is a radar that detects a front obstacle using radio waves or infrared rays.
The sensor 451 is a radar that detects a rear obstacle using radio waves or infrared rays.
More specifically, the sensor 450 determines the vehicle position and the traveling direction by combining information obtained from the GPS, direction sensor, and vehicle speed sensor and map information. Further, it is determined from the map information whether the vehicle is approaching an intersection or curve with poor visibility, and the information is output to the communication control device 110.
The sensor 451 detects the approach of a front obstacle such as a pedestrian, a forward traveling vehicle, and an oncoming vehicle by radio waves or infrared radar, and outputs the information to the communication control device 110.
The sensor 452 detects the approach of a rear obstacle such as a pedestrian or a rear traveling vehicle by radio wave or infrared radar, and outputs the information to the communication control device 110.

FIG. 5 shows an example of a bandwidth allocation table in the second embodiment.
In the normal state, a bandwidth is allocated to entertainment-type terminals such as a playback device and a broadcast receiving device, and when the overall communication bandwidth is reduced, the overall bandwidth is reduced in proportion to it.
If the forward direction is poor, a bandwidth is allocated to the front camera with priority, and a bandwidth to be allocated to the front camera is secured even if the overall effective communication bandwidth drops.
When an obstacle approaches the front, a bandwidth is assigned to the front camera with priority, and even if the overall effective communication bandwidth is reduced, the bandwidth assigned to the front camera is not dropped at all.
On the other hand, when an obstacle approaches the rear, a bandwidth is assigned to the rear camera with priority, and even if the overall effective communication bandwidth is reduced, the bandwidth assigned to the rear camera is not reduced at all.

FIG. 8 shows a configuration of communication control apparatus 110 according to the present embodiment.
The configuration of FIG. 8 is the same as the configuration of FIG. 6 except that a sensor I / F unit 1107 is provided instead of the electronic control device I / F (interface) unit 1106.
The sensor I / F unit 1107 inputs sensor information indicating measurement results and determination results of the sensors 450 to 452.
Further, in the present embodiment, the state determination unit 1105 determines that the state of the surrounding environment of the vehicle is “normal state”, “progressive line-of-sight”, “forward obstacle” shown in the driving state of FIG. 5 based on the sensor information. It is determined whether it is “approaching an object” or “approaching an obstacle behind”.
Further, the information storage unit 1104 according to the present embodiment stores the bandwidth allocation table shown in FIG.
In addition, the communication band determining unit 1103 according to the present embodiment selects the subband corresponding to the determination result of the state determination unit 1105 and the effective band measured by the wireless communication device 111 from the subtables of the band allocation table of FIG. Select a table.
The operation of other elements is the same as that of the first embodiment.

FIG. 9 is a flowchart showing an operation example of the communication control apparatus 110 according to the present embodiment.
In addition, the same code | symbol as FIG. 7 is attached | subjected to the process similar to FIG.

First, the sensor I / F unit 1107 inputs sensor information from the sensors 450 to 452, inputs and outputs the sensor information to the state determination unit 1105, and the state determination unit 1105 based on the sensor information determines the driving situation (the surroundings of the vehicle The environmental state is determined (S901).
Further, the state determination unit 1105 outputs the determination result to the communication band determination unit 1103.
Next, the wireless communication apparatus I / F unit 1101 receives band information for notifying the effective band from the wireless communication apparatus 111, outputs the received band information to the communication band determination unit 1103, and the communication band determination unit 1103 The effective bandwidth indicated in the information is confirmed (S702).
Note that the order of S901 and S702 may be switched.

The communication band determining unit 1103 stores the previous driving situation and the effective band, and the current driving situation (the state determined in S901) and the effective band (the effective band confirmed in S702) are the previous driving state and It is determined whether or not there is a change in the effective band (S703). If there is no change in both the operation status and the effective band, the process is terminated. On the other hand, if there is a change in at least one, the band of FIG. From the allocation table, a sub-table corresponding to the current operation status and effective bandwidth is extracted (S704).
When the current effective bandwidth is other than the value shown in the bandwidth allocation table of FIG. 5, for example, when the vehicle is currently in the “normal state” and the effective bandwidth is “18 Mbps”, the effective bandwidth “ Since it is equal to or greater than “16 Mbps” and less than “20 Mbps”, the sub-table Table1-2 is selected.

Next, the communication band determining unit 1103 determines a radio communication band to be allocated to each terminal based on the extracted subtable (S705).
For example, the bandwidth of each terminal indicated in the selected sub-table may be used as it is. As described above, when the current effective bandwidth is other than the value indicated in the bandwidth allocation table of FIG. The bandwidth of each terminal may be calculated based on the difference between the actual effective bandwidth and the effective bandwidth of the selected sub-table.
Subsequent operations are the same as those in FIG. 7 described in the first embodiment, and a description thereof will be omitted.

  The vehicle parameters described in the first embodiment and the vehicle surroundings described in the second embodiment may be combined with the parameters of the table for determining the transmission allocation bandwidth of each terminal.

  In the first and second embodiments, all video signals are communicated wirelessly. However, some video signals may be wired, and some control signals may be wired. However, these may be communicated wirelessly.

  As described above, in this embodiment, since the communication control apparatus can change the transmission band allocation ratio according to the size of the transmission band, the transmission band of the important video data determined by the surrounding situation of the vehicle varies. Even so, it can be transmitted in real time while maintaining the required accuracy.

As described above, in the present embodiment,
An image pickup device that captures a state outside or inside the vehicle, a playback device that reads a video source from a medium, such as a DVD player or a Blu-ray (registered trademark) disk player, a broadcast receiver that receives broadcast radio waves, and video data are displayed. Consists of a display device, a wireless communication device that performs wireless communication in the vehicle, a sensor that measures the situation around the vehicle, such as the position of the vehicle and the distance to obstacles, and a communication control device that controls the communication band between each terminal In-vehicle system
It has been explained that the communication control apparatus can change the allocation ratio of the transmission band according to the size of the transmission band when allocating the communication band to each terminal according to the information obtained from the sensor.

2 and 5 show a plurality of effective bandwidth levels (20 Mbps, 16 Mbps, 12 Mbps, and 8 Mbps), and sub-tables are provided for each level. The effective band value may be used.
For example, only the sub-tables Tables 1-1, 2-1, 3-1, 4-1, and 5-1 that are sub-tables with an effective bandwidth of 20 Mbps may be provided in the bandwidth allocation table.
When such a band allocation table is used, the communication band determination unit 1103 calculates the allocated band of each terminal in correspondence with the difference between the actually measured effective band and the effective band of 20 Mbps.
For example, when the bandwidth allocation table of FIG. 2 is used, when the operation status is “stopped” and the actually measured effective bandwidth is “16 Mbps”, the sub-table Table1-1 is selected. Calculate as follows.
Front camera bandwidth: (16/20) × 2 = 1.6 Mbps
Rear camera bandwidth: (16/20) × 2 = 1.6 Mbps
Band of playback device: (16/20) × 8 = 6.4 Mbps
Broadcast receiver bandwidth: (16/20) × 8 = 6.4 Mbps
The calculation method is not limited to this.

Finally, a hardware configuration example of the communication control apparatus 110 shown in the first and second embodiments will be described.
FIG. 10 is a diagram illustrating an example of hardware resources of the communication control apparatus 110 illustrated in the first and second embodiments.
The configuration in FIG. 10 is merely an example of the hardware configuration of the communication control device 110, and the hardware configuration of the communication control device 110 is not limited to the configuration illustrated in FIG. Also good.

In FIG. 10, the communication control device 110 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, a processing unit, a microprocessor, a microcomputer, and a processor) that executes a program.
The CPU 911 is connected to, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a communication board 915, and a magnetic disk device 920 via the bus 912, and controls these hardware devices.
Further, instead of the magnetic disk device 920, a storage device such as an SSD (Solid State Drive), an optical disk device, or a memory card (registered trademark) read / write device may be used.
The RAM 914 is an example of a volatile memory. The storage medium of the ROM 913 and the magnetic disk device 920 is an example of a nonvolatile memory. These are examples of the storage device.
The “information storage unit 1104” described in the first and second embodiments is realized by the RAM 914, the magnetic disk device 920, and the like.
The communication board 915 is an example of an input device and an output device.

  The communication board 915 is connected to the wireless communication device 111, the electronic control device 150, or the sensors 450 to 452.

The magnetic disk device 920 stores an operating system 921 (OS), a program group 923, and a file group 924.
The programs in the program group 923 are executed by the CPU 911 using the operating system 921.

The RAM 914 temporarily stores at least part of the operating system 921 program and application programs to be executed by the CPU 911.
The RAM 914 stores various data necessary for processing by the CPU 911.

The ROM 913 stores a BIOS (Basic Input Output System) program, and the magnetic disk device 920 stores a boot program.
When the communication control device 110 is activated, the BIOS program in the ROM 913 and the boot program in the magnetic disk device 920 are executed, and the operating system 921 is activated by the BIOS program and the boot program.

  The program group 923 stores programs that execute the functions described as “˜units” (other than “information storage unit” in the following) in the description of the first and second embodiments. The program is read and executed by the CPU 911.

In the file group 924, in the description of the first and second embodiments, “determination of”, “determination of”, “calculation of”, “comparison of”, “extraction of”, and “determination of” ”,“ Setting of ”,“ generation of ”,“ selection of ”, etc., information, data, signal values, variable values, and parameters indicating the results of the processing, It is stored as each item of “Database”.
The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory. Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit, and extracted, searched, referenced, compared, and calculated. Used for CPU operations such as calculation, processing, editing, and output.
Information, data, signal values, variable values, and parameters are temporarily stored in the main memory, registers, cache memory, buffer memory, etc. during the CPU operation for extraction, search, reference, comparison, calculation, calculation, processing, editing, and output. Memorized.
The arrows in the flowcharts described in the first and second embodiments mainly indicate input / output of data and signals. The data and signal values are the memory of the RAM 914, the magnetic disk of the magnetic disk device 920, the SSD, and the like. It is recorded on a recording medium such as an optical disk or DVD. Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

In addition, what is described as “˜unit” in the description of the first and second embodiments may be “˜circuit”, “˜device”, “˜device”, and “˜step”, It may be “˜procedure” or “˜processing”.
That is, the operation of the communication control apparatus 110 can be grasped as a method by the steps, procedures, and processes shown in the flowcharts described in the first and second embodiments.
Further, what is described as “˜unit” may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware. Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes the computer to function as “to part” in the first and second embodiments. Alternatively, the computer executes the procedure and method of “to unit” in the first and second embodiments.

  As described above, the communication control device 110 described in the first and second embodiments is a computer including a communication board serving as an input device and an output device such as a CPU serving as a processing device, a memory serving as a storage device, and a magnetic disk. The functions indicated as “˜units” are realized using these processing devices, storage devices, input devices, and output devices.

  DESCRIPTION OF SYMBOLS 100 In-vehicle system, 110 Communication control apparatus, 111 Wireless communication apparatus, 120 Imaging apparatus, 121 Wireless communication apparatus, 130 Imaging apparatus, 131 Wireless communication apparatus, 140 Playback apparatus, 141 Wireless communication apparatus, 150 Electronic control apparatus, 160 Broadcast receiving apparatus 161 wireless communication device 170 display device 180 display device 181 wireless communication device 450 sensor 451 sensor 452 sensor 1101 wireless communication device I / F unit 1102 communication band notification unit 1103 communication band determination unit 1104 Information storage unit, 1105 state determination unit, 1106 electronic control device I / F unit, 1107 sensor I / F unit.

Claims (10)

A plurality of data transmission devices that wirelessly transmit data, and a communication control device that is mounted on a vehicle together with a data reception device that wirelessly receives data from each data transmission device and measures a wireless communication band at the time of data reception Because
A state determination unit for determining the state of the vehicle;
Communication for determining a wireless communication band to be assigned for each data transmission device based on the state of the vehicle determined by the state determination unit, the attribute of each data transmission device, and the wireless communication bandwidth measured by the data reception device A bandwidth determination unit;
A communication control apparatus comprising: a communication band notification unit that notifies each data transmission device of the wireless communication band determined by the communication band determination unit. The communication control device further includes:
A plurality of vehicle states, and allocation ratio information indicating an allocation ratio of a wireless communication band allocated to each data transmission device for each state, and the vehicle when the vehicle is in that state for each state An information storage unit that stores allocation ratio information in which a higher allocation ratio is set for a data transmission device that transmits data estimated to be important to the
The state determination unit
Determining which state of the plurality of states indicated by the allocation ratio information corresponds to the state of the vehicle;
The communication band determining unit
The wireless communication band to be allocated is determined for each data transmission device based on an allocation ratio corresponding to the state determined by the state determination unit and a wireless communication band measured by the data reception device. The communication control apparatus according to 1. The information storage unit
A plurality of states and a plurality of stages of radio communication band levels are indicated, and for each combination of the state and the radio communication band level, allocation ratio information indicating an allocation ratio of a radio communication band allocated to each data transmission device is stored,
The state determination unit
Determining which state of the plurality of states indicated by the allocation ratio information corresponds to the state of the vehicle;
The communication band determining unit
Determining which radio communication band level the radio communication band level measured by the data receiving device corresponds to among the plurality of stages of radio communication band levels;
The radio communication band to be allocated to each data transmission device is determined based on an allocation ratio corresponding to a combination of the determined radio communication band level and the state determined by the state determination unit. Communication control device. The information storage unit
A data transmission device that transmits data that is presumed to be important for passengers of the vehicle even when the wireless communication band level is low, stores allocation ratio information in which the wireless communication band is preferentially allocated. The communication control device according to claim 3. The information storage unit
5. The allocation ratio information indicating at least one of a plurality of states related to traveling of the vehicle and a plurality of states related to a surrounding environment of the vehicle is stored as the plurality of states. The communication control apparatus in any one. The state determination unit
The state of the vehicle is determined using at least one of information output from an electronic control device that controls the traveling of the vehicle and information output from a sensor that monitors the surrounding environment of the vehicle. The communication control apparatus according to claim 5. An in-vehicle system mounted on a vehicle,
A plurality of data transmission devices for wirelessly transmitting data;
A data receiving device that wirelessly receives data from each data transmitting device and measures a wireless communication band at the time of data reception; and
A radio assigned to each data transmission device for each data transmission device based on the determined vehicle state, the attribute of each data transmission device, and the wireless communication band measured by the data reception device. A communication control unit that determines a communication band and notifies each data transmission device of the determined wireless communication band;
Each data transmission device
A vehicle-mounted system that performs data transmission in a wireless communication band notified by the communication band determining unit. The communication control device includes:
The state of the vehicle is determined using at least one of information output from an electronic control device that controls the traveling of the vehicle and information output from a sensor that monitors the surrounding environment of the vehicle. The in-vehicle system according to claim 7. Each data transmission device
Based on the effective communication bandwidth, calculate the transmission completion time to complete the transmission of data waiting for transmission,
When the calculated transmission completion time exceeds a predetermined threshold, the encoding rate of newly generated data is less than the encoding rate corresponding to the wireless communication band notified by the communication control device The in-vehicle system according to claim 7 or 8, wherein Each data transmission device
Send at least one of camera data, video data, audio data, text data, received data received from outside the vehicle,
The data receiving device is:
The at least one of the camera photographing data, the video data, the audio data, the character data, and the reception data is received, and the received data is output. In-vehicle system.

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