JP4096705B2 - In-vehicle communication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle-mounted communication system that connects various vehicle-mounted devices mounted on a vehicle wirelessly or by wire.
[0002]
[Prior art]
A large number of in-vehicle devices such as a navigation device, a CD changer, an ETC unit, and a TEL-LINK unit are mounted in the vehicle, and these are connected by an in-vehicle LAN (local area network).
[0003]
Also, as described in, for example, Japanese Patent Application Laid-Open No. 11-353586 (Patent Document 1), some of the in-vehicle devices are equipped with a narrow area wireless communication system, and the narrow area wireless communication Data transmission between each in-vehicle device is performed using the system.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-353586
[Problems to be solved by the invention]
Conventional narrow-area wireless communication systems are low in transmission power, and thus are susceptible to the effects of the number of passengers on the vehicle, the installation locations of various in-vehicle devices, and the like, and communication errors may occur. In particular, when an in-vehicle device is mounted in the trunk behind the vehicle, the communication distance becomes long, so that a communication error is remarkable.
[0006]
Further, since the wireless LAN and the wired LAN are not connected at the same time, there is a problem that wireless data cannot be communicated when the communication rate of wireless communication is deteriorated.
[0007]
Further, since the wireless BER (Bit Error Rate) is not provided with a function of determining the wireless error rate, there is a disadvantage that wireless data cannot be communicated when the communication rate of the wireless communication is deteriorated.
[0008]
The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an in-vehicle communication system capable of reliably transmitting data even when the communication rate is deteriorated. It is in.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 of the present application has a plurality of in-vehicle devices, and two or more in-vehicle devices among the in-vehicle devices can communicate with each other by wireless communication means. Alternatively, in a vehicle-mounted communication system in which two or more different vehicle-mounted devices are connected by wired communication means, the first vehicle-mounted device can communicate with the first vehicle-mounted device by wireless communication means, and the Internet line and wireless in comprising: a second vehicle-mounted device capable of communicating, connected by said first in-vehicle device and the wired communication means, and a third of the in-vehicle apparatus that is capable of communicating by said second in-vehicle apparatus and the wireless communication means The first in-vehicle device is detected by the communication rate detecting unit between a communication rate detecting unit that detects a communication rate during wireless communication and a second in-vehicle device that is a target of wireless communication. When the communication rate deteriorates Has, a transmission switching control means for switching operation to communicate with a wired communication means between said third vehicle device, the third vehicle apparatus, the first vehicle unit Relay transmission control means for performing control to communicate with the second in-vehicle device using wireless communication means via the wired communication means, and further, the transmission switching control means includes the first in-vehicle device and When the communication rate with the second in-vehicle device becomes good, control is performed to switch to wireless communication between the first in-vehicle device and the second in-vehicle device.
[0010]
【The invention's effect】
In the in-vehicle communication system according to the present invention, when the communication rate between the first in-vehicle device and the second in-vehicle device is deteriorated, the first in-vehicle device and the third in-vehicle device using the wired communication means. The device is connected, and further, communication by the wireless communication means is performed between the third in-vehicle device and the second in-vehicle device. Therefore, even if the communication rate between the first in-vehicle device and the second in-vehicle device is deteriorated, the first in-vehicle device reliably communicates with the second in-vehicle device through the third in-vehicle device. Therefore, it is possible to avoid the occurrence of trouble that communication is interrupted due to the installation location of the first in-vehicle device, the number of passengers, the seating position of the passengers, and the like.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an in-vehicle communication device according to an embodiment of the present invention. As shown in the figure, the in-vehicle communication system 1 includes a navigation device 2 (first in-vehicle device, route guidance device), a mobile phone (second in-vehicle device) 3, and a radio device (third in-vehicle device). Device, audio device) 4.
[0012]
The navigation device 2 is installed, for example, in the trunk at the rear of the vehicle or in the lower part of the seat, and the radio device 4 is installed, for example, in a dashboard. The navigation device 2 and the radio device 4 are connected by an in-vehicle LAN (wired communication means) 5 so that data can be transmitted to each other.
[0013]
In addition, the navigation device 2, the radio device 4, and the mobile phone 3 have narrow-area wireless communication units (wireless communication means) 2a, 3a, and 4a, respectively, through which wireless communication is possible. ing.
[0014]
FIG. 2 is a block diagram showing a detailed configuration of the navigation device 2 and the radio device 4. As shown in the figure, the navigation device 2 acquires a narrow area wireless communication unit 2a, a CD reader 2b that reads a CDROM in which map data is written, an operation unit 2c that performs various operation inputs, and GPS data. GPS receiver 2d, display unit 2e for displaying map data and vehicle current location data on a screen, CPU (transmission switching control means) 2f, memory 2g, power supply circuit 2h, and communication rate detection unit (communication rate detection unit) ) 2i.
[0015]
The communication rate detection unit 2i detects a BER (code error rate; communication rate) of communication using the narrow area wireless communication unit 2a.
[0016]
The CPU 2f controls the navigation device 2 as a whole, and the communication rate detected by the communication rate detection unit 2i deteriorates when wireless communication is performed with the mobile phone 3 using the narrow area wireless communication unit 2a. If it is determined that the wireless communication is performed, control is performed to perform wireless communication with the mobile phone 3 via the wired LAN 5 and the radio device 4.
[0017]
Furthermore, when the communication rate with the mobile phone 3 becomes favorable, control is performed to switch to wireless communication using the narrow area wireless communication unit 2a again.
[0018]
The CPU 2f has a function of connecting to the Internet via the mobile phone 3 and browsing information related to the Internet.
[0019]
The radio device 4 includes a narrow area wireless communication unit 4a, a tuner 4b, a speaker 4c, and a CPU (relay transmission control means) 4d.
[0020]
The CPU 4d generates a sound signal from the radio wave received by the tuner 4b and performs control to output the sound signal to the speaker 4c, and transmits the transmission data transmitted from the navigation device 2 via the in-vehicle LAN 5 to the narrow area wireless communication unit 4a. Is transmitted to the mobile phone 3, and transmission data transmitted from the mobile phone 3 is received and transmitted to the navigation device 2.
[0021]
Next, the operation of the in-vehicle communication system according to the present embodiment will be described with reference to the flowchart shown in FIG.
[0022]
Here, as an example, a case will be described in which navigation device 2 is wirelessly connected to mobile phone 3 having a narrow-area wireless communication function and connected to the Internet using a dial-up profile.
[0023]
First, when the power is turned on (step ST1), initial setting is performed (step ST2). Next, in order to connect to the Internet using the navigation device 2, the mobile phone 3 is connected by narrow area wireless communication (step ST3). Thereafter, the mobile phone 3 is dialed up to connect to the Internet (step ST4).
[0024]
Next, the communication rate detection unit 2i of the navigation device 2 detects a BER (Bit Error Rate) of narrowband wireless communication (step ST5), and when it is detected that the BER has deteriorated (step ST5). In step ST5, YES, communication is performed with the radio device 4 via the in-vehicle LAN 5, and a switching operation is performed to perform wireless communication with the mobile phone 3 using the narrow area wireless communication unit 4a included in the radio device 4 (step). ST6).
[0025]
Thereafter, it is determined whether or not the BER has been improved (step ST7). If the BER has been improved (YES in step ST7), the switching operation is performed to communicate with the radio device 4 via the in-vehicle LAN 5 and restore the wireless communication. That is, a switching operation is performed to perform wireless communication with the mobile phone 3 using the narrow area wireless communication unit 2a of the navigation device 2 (step ST8).
[0026]
In this way, even when the communication rate between the navigation device 2 and the mobile phone 3 is deteriorated, reliable communication can be performed.
[0027]
In this way, in the in-vehicle communication system 1 according to the present embodiment, when the communication rate between the navigation device 2 and the mobile phone 3 deteriorates, the navigation device 2 and the radio device 4 are connected using the in-vehicle LAN 5. Is further connected, and wireless communication with the mobile phone 3 is performed via the narrow-area wireless communication unit 4a of the radio device 4. Accordingly, the navigation device 2 can reliably communicate with the mobile phone 3 via the radio device 4 even when wireless communication with the mobile phone 3 is disabled. Due to the location, the number of passengers, the seating position of the passengers, and the like, it is possible to avoid troubles such as communication being interrupted.
[0028]
As mentioned above, although the vehicle-mounted communication system of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part is replaced with the thing of the arbitrary structures which have the same function. be able to.
[0029]
For example, in the present embodiment, an example in which the navigation device 2, the mobile phone 3, and the radio device 4 are provided as in-vehicle devices has been described. However, the present invention is not limited to this, and the present invention is also applicable to other in-vehicle devices. can do.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an in-vehicle communication system according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a detailed configuration of a navigation device and a radio device.
FIG. 3 is a flowchart showing a processing procedure of the in-vehicle communication system according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle-mounted communication system 2 Navigation apparatus (1st vehicle-mounted apparatus)
2a Narrow Wireless Communication Unit 2b CD Reader 2c Operation Unit 2d GPS Receiver 2e Display Unit 2f CPU
2g Memory 2h Power supply circuit 2i Communication rate detector 3 Mobile phone (second in-vehicle device)
3a Narrow-area wireless communication unit 4 Radio device (third in-vehicle device)
4a Narrow Wireless Communication Unit 4b Tuner 4c Speaker 4d CPU
5 In-car LAN

Claims (3)

A plurality of in-vehicle devices, two or more of the in-vehicle devices can be communicated by wireless communication means, and two or more in-vehicle devices that are the same or different from each other are connected by wired communication means. In a communication system,
A first in-vehicle device;
A second in-vehicle device capable of communicating with the first in-vehicle device by wireless communication means and capable of communicating with the Internet line wirelessly;
Which is connected in the first vehicle apparatus and wire communication means, and of which a third of the in-vehicle apparatus that is capable of communicating by said second in-vehicle apparatus and the wireless communication means,
The first in-vehicle device is
Communication rate detecting means for detecting a communication rate during wireless communication;
When the communication rate detected by the communication rate detecting means with the second in-vehicle device that is the target of wireless communication deteriorates, the wired communication means is used with the third in-vehicle device. Transmission switching control means for performing a switching operation for communication,
The third in-vehicle device includes a relay transmission control unit that performs control to communicate from the first in- vehicle device to the second in-vehicle device using a wireless communication unit via the wired communication unit,
Furthermore, the transmission switching control means, when the communication rate between the first in-vehicle device and the second in-vehicle device becomes good, between the first in-vehicle device and the second in-vehicle device. The vehicle-mounted communication system characterized by performing control which switches to wireless communication between.   The first on-vehicle device is one of a route guidance device and an audio device, and the third on-vehicle device is the other of the route guidance device and the audio device. The vehicle-mounted communication system according to 1.   The in-vehicle communication system according to claim 1, wherein the second in-vehicle device is a mobile phone mounted on a vehicle.

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