JPH1084568A - Data communication device - Google Patents

Abstract

(57) [Summary] To provide a data communication device capable of efficiently performing data communication. A communication line selection signal provided from a CPU (13) to a communication line switching device (21) via a line (25) is a signal generated based on a moving speed of a vehicle. For example, when a moving speed is 20 km / h or more, A signal indicating that a mobile phone line should be used is created, and the moving speed is 20k.
When the speed is less than m / h, a signal indicating that the PHS line should be used is generated. The communication line switching device 21 switches the communication line to be used between the mobile phone line and the PHS line based on the communication line selection signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a data communication system used in combination with an in-vehicle navigation device for transmitting and receiving various data to and from an information center holding road map information and traffic information. Related to the device.

[0002]

2. Description of the Related Art Conventionally, there has been known an on-vehicle navigation device which detects a current position of a vehicle and displays the current position on a display together with a road map around the vehicle in order to facilitate the running of the vehicle. I have. In such a navigation device, the road map around the current position is usually stored in a road map memory constituted by, for example, a CD-ROM, and read out from the road map memory as needed and displayed. You.

However, the above navigation device can only display a road map previously stored in a road map memory, and cannot display a newly opened road or the like on a display. To display this newly opened road, a CD that incorporates the information of the road
It may be replaced with a ROM, but it takes some time before the road information is taken into the CD-ROM, so that the latest road information cannot always be displayed.

On the other hand, it is more convenient if the navigation device can display not only the current position of the vehicle and a road map but also information such as traffic congestion information, accident / construction information, road regulation information, and weather forecast. Can be a device. In recent years, a communication line such as a mobile phone line connects a navigation device or the like mounted on a vehicle to an information center or the like, and provides the road map information and the various types of information from the information center to the navigation device. Research and development of the system is underway.

For example, Japanese Unexamined Patent Publication No. Hei 4-266228 discloses that the current position information of a vehicle detected by a GPS (Global Positioning System) device is transmitted to an information center through an automobile telephone line, and road map information and road information near the current position are transmitted. An apparatus has been disclosed in which regulation information and the like are returned from an information center and displayed on a display. According to this device, since the latest information such as a road map can be always obtained, it is possible to cope with the opening of a new road or a change in traffic regulation.

[0006]

When an automobile telephone line or a mobile telephone line is used as a communication line for connecting an information center and a navigation device, the communication speed is 9600 bps (bits per second) at the maximum.
Therefore, in the device disclosed in the above publication,
When the amount of information received from the information center is large, data transmission takes a long time.

To solve such a problem, a PHS (Pers Pers) capable of transmitting data at a maximum of 32 kbps is available.
onal Handy-phone System) A line may be used as a communication line.
The area (cell) covered by the S base station has a radius of about 50 to 1
In addition to being as narrow as about 00m, the function of switching base stations without interrupting the call when a vehicle moves from the cell of the currently communicating PHS base station to an adjacent cell, the so-called handover function, is used for automobile telephone lines and mobile phones. Since it is simpler than a line, communication becomes impossible during high-speed movement.

Accordingly, an object of the present invention is to solve the above-mentioned technical problems and to provide a data communication device capable of efficiently performing data communication with an information center holding road map information and traffic information, for example. To provide.

[0009]

According to a first aspect of the present invention, there is provided a data communication device which is applied to a navigation device having a speed detecting means for detecting a moving speed of a moving body, and is provided outside the moving body. A data communication device for communicating various data with the communication device of the present invention, comprising a plurality of communication means capable of communicating with a communication device external to the moving object, and a moving speed of the moving object detected by the speed detecting means at the start of the communication. And selecting means for selecting one of the plurality of communication means, and communicating various data using the communication means selected by the selecting means.

According to the first aspect of the present invention, one of the plurality of communication means is selected by the selection means in accordance with the moving speed of the moving object detected by the speed detection means provided in the navigation device. You. For example, during high-speed movement, a communication means that can be used even when moving at high speed is selected, so that the moving body does not lose communication due to high-speed movement. Thus, the most suitable communication means can be used according to the moving speed of the moving object.

Since the speed detecting means is usually provided in the navigation device, it is not necessary to newly attach a sensor or the like for detecting the moving speed of the moving body to the moving body. Is easy. Claim 2
The described data communication device is a data communication device mounted on the mobile body, for communicating various data with a communication device outside the mobile body, a plurality of communication means that can communicate with the communication device outside the mobile body, One of a plurality of communication means according to a speed detecting means for detecting a moving speed of the moving body and a moving speed of the moving body detected by the speed detecting means at the start of communication.
And selecting means for selecting one of the two, and communicating various data using the communication means selected by the selecting means.

[0012] According to the configuration of the second aspect, similarly to the first aspect of the invention, the most suitable communication means can be used according to the moving speed of the moving body. For example, it can be connected to a personal computer or a facsimile machine and used for personal computer data communication or facsimile communication. According to a third aspect of the present invention, the plurality of communication units include a first communication unit having a relatively low communication speed and a second communication unit having a relatively high communication speed. A determination unit configured to determine whether a moving speed of the moving object detected by the speed detection unit at the start of the communication is equal to or higher than a predetermined speed; and the determination unit determines that the moving speed is the predetermined speed. 2. The method according to claim 1, wherein the first communication unit is selected when it is determined that the above is the case, and the second communication unit is selected when it is determined that the moving speed is lower than the predetermined speed. Or a data communication device according to claim 2.

According to the third aspect of the invention, when the speed is determined to be higher than the predetermined speed by the determining means, the first communication means having a relatively low communication speed is selected by the selecting means, and the first communication means is selected. Communication of various data with a communication device outside the mobile body is performed using the communication means. When the moving speed of the moving object is determined to be lower than the predetermined speed by the determining means, the second communicating means having a relatively high communication speed is selected by the selecting means, and the second communicating means is used. The communication of various data with the communication device outside the mobile body is performed. Therefore, of the two communication means, the communication means that is suitable for the moving speed at that time can be used.

According to a fourth aspect of the present invention, the first communication means is a portable telephone or a car telephone, and the second communication means is a second telephone.
4. The data communication device according to claim 3, wherein the communication means is a PHS machine. According to the configuration of the fourth aspect, when the moving speed of the moving body is equal to or higher than the predetermined speed, the moving body is communicated with the communication device outside the moving body using the mobile phone line or the car telephone line, and the moving speed of the moving body is set to the predetermined speed. When the speed is lower than the predetermined speed, communication is performed with a communication device outside the mobile body using the PHS machine.

In general, the communication speed when using a cellular phone and a car phone line is 9600 bps at the maximum.
Since the maximum speed is 32 kbps when a PHS line is used, using a PHS line requires less time for data transmission and is more efficient. Further, at present, the telephone charge of the PHS line is lower than the telephone charge of the mobile telephone line. However, when the cell of one PHS base station is narrow and the vehicle moves from the cell of the currently communicating PHS base station to the adjacent cell, the communication from the communicating PHS base station to the adjacent PHS base station is performed. Since the switching speed is slow, communication becomes impossible if the moving body moves at high speed.

According to the fourth aspect of the present invention, a portable telephone or an automobile telephone and a PHS machine are selected and used according to the moving speed of a moving body,
Data can be transmitted efficiently.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a system for providing road map information, traffic information, and the like to a vehicle equipped with a data communication device according to the present invention. This information providing system includes a mobile phone base station 1 installed in a mobile phone service area and a PHS (Personal
al Handy-phone System), a PHS base station 2 installed in a service area, a mobile phone base station 1 and a PHS
Information center 4 connected to base station 2 via telephone line 3
And Note that the mobile phone base station 1 and the PHS
A plurality of base stations 2 are provided for each predetermined area.

The information center 4 stores, for example, information such as road map information, traffic information including traffic congestion information, accident / construction information, road regulation information, and weather forecast. For example, road map information is obtained by dividing a road map (including highway national roads, motorways, other national roads, prefectural roads, city roads of designated cities, and other living roads) into meshes, and is stored in mesh units. I have. More specifically, the road map information is composed of a node that is a coordinate position for specifying an intersection or a bending point of a road, and a link unit that is a vector connecting the nodes,
It is stored as data such as the coordinates of the start point node and end point node of each link and the link number of each link. Further, for example, traffic information is stored as data such as link numbers corresponding to traffic jams and roads subject to regulation.

When the information center 4 receives the current position data of the vehicle 5 from the vehicle 5 via a mobile telephone line or a PHS telephone line, the information center 4 transmits road map information and traffic information near the current position to the mobile telephone line or The data is transmitted to the vehicle 5 via the PHS telephone line. FIG. 2 shows the vehicle 5 shown in FIG.
FIG. 2 is a block diagram illustrating an electrical configuration of a navigation device and a data communication device mounted on the vehicle. The data communication device 20 for transmitting and receiving various data between the navigation device 10 and the information center 4 (see FIG. 1)
Is mounted on the vehicle 5 shown in FIG.

The navigation device 10 includes a GPS (Gl
The GPS receiver 11 for receiving a signal from an obal positioning system (satellite) is provided, and a signal received by the GPS receiver 11 is provided to a position detection unit 12. The position detector 12 calculates the current position of the vehicle 5 based on a signal input from the GPS receiver 11. Specifically, the current position of the vehicle 5 is calculated based on the propagation time difference between the transmission signals of a plurality of GPS satellites. This calculation of the current position of the vehicle is repeated at regular intervals (for example, every one second).

Note that, instead of the GPS receiver 11,
Outputs of an azimuth sensor for detecting an amount of change in the azimuth of the vehicle 5 and a vehicle speed sensor 14 to be described later may be provided to the position detector 12, and the current position of the vehicle 5 may be detected based on these outputs. More specifically, the traveling direction of the vehicle 5 is determined based on the output of the direction sensor, the traveling distance of the vehicle is determined based on the output of the vehicle speed sensor 14, and the predetermined initial position of the vehicle 5 is determined. The traveling direction and the traveling distance of the vehicle 5 thus obtained are accumulated, and the current position of the vehicle 5 is calculated. In this case, road map information for detecting the current position is stored in a memory (not shown).

The current position data calculated as described above is given to the CPU 13. The CPU 13 functions as a control center of the navigation device 10. To the CPU 13, in addition to the current position data output from the position detection unit 12, for example, an output from a vehicle speed sensor 14 configured by a wheel speed sensor that detects a rotation speed of a tire wheel of the vehicle 5 is given. The CPU 13 detects the moving speed of the vehicle 5 based on the output of the vehicle speed sensor 14.

The CPU 13 further includes a data communication device 2
A received information holding unit 17 for holding the information received by 0 and a display 16 via a display control unit 15 are connected. Various kinds of information received by the data communication device 20 are temporarily stored in the reception information holding unit 17 by the CPU 13, read out, and provided to the display control unit 15. As a result, the display 16 shows
The content of the information received by the data communication device 20 is displayed. When the current position data of the vehicle 5 input from the position detection unit 12 to the CPU 13 is given to the display control unit 15, the current position of the vehicle 5 is displayed in a manner superimposed on the road map.

The data communication device 20 is connected to the navigation device 10 and communicates with the mobile phone base station 1 (see FIG. 1) via a mobile phone line. Station (see FIG. 1)
A PHS machine 23 for performing communication via an HS line and a communication line switching device 21 for switching a communication line to be used between a mobile phone line and a PHS line are provided.

The communication line switching device 21 is connected to the CPU 13 of the navigation device 10 via lines 24 and 25. The line 24 is used to transmit various data between the CPU 13 and the communication line switching device 21. Road map information and traffic information transmitted from the information center 4 (see FIG. 1) are transmitted through the line 24. Via CP
It is given to U13. Further, the current position data calculated by the position detection unit 12 is provided to the communication line switching device 21 via the line 24.

CPU 13 provides a communication line selection signal via line 25 to communication line switching device 21 for instructing whether communication with information center 4 is to be carried out on a portable telephone line or a PHS line. This communication line selection signal is
This signal is generated based on the moving speed of the vehicle 5, and for example, the moving speed is 20 immediately before selecting the telephone line.
When the speed is equal to or higher than km / h, a signal indicating that the mobile phone line should be used is generated. When the moving speed is lower than 20 km / h, a signal indicating that the PHS line should be used is generated. The communication line switching device 21 switches a communication line to be used between a mobile telephone line and a PHS line based on a communication line selection signal given from the CPU 13.

As described above, according to the moving speed of the vehicle 5,
The communication line connected to the information center 4 is a mobile phone line and P
Switching to the HS line is one of the features of the present invention. The communication speed when using a mobile phone line is 9600 bps (bits per second) at the maximum.
Since the maximum speed is 32 kbps when the S line is used, the use of the PHS line requires less time for data transmission and is more efficient. Further, at present, the telephone charge of the PHS line is lower than the telephone charge of the mobile telephone line. However, in the PHS line, the area (cell) covered by one PHS base station is narrow with a radius of about 50 to 100 m, and when a vehicle moves from a cell of the currently communicating PHS base station to an adjacent cell, Since the function of switching base stations without interrupting the call, the so-called handover function, is simplified as compared with the mobile phone line and the mobile phone line, communication becomes impossible during high-speed movement. Therefore, in the data communication device 20 according to the present invention, the data transmission is efficiently performed by automatically switching the communication line to be used according to the moving speed of the vehicle 5.

FIG. 3 is a flowchart showing the flow of the control operation of the CPU 13. In the following, according to the flow of the flowchart shown in FIG. 3 with reference to FIGS. 1 and 2,
The control operation of the CPU 13 will be described in detail. Vehicle 5
Starts running, the CPU 13 controls the position detection unit 12 to calculate the current position of the vehicle 5 based on signals from GPS satellites received by the GPS receiver 11 (step S1). Further, the moving speed of the vehicle 5 is detected based on the output of the vehicle speed sensor 14 (Step S2).
The calculation of the current position and the detection of the moving speed are performed at regular intervals, and the CPU 13 always holds the latest current position data and moving speed data.

Next, the CPU 13 determines whether or not to communicate with the information center 4 using the telephone line (step S3). When the communication with the information center 4 is not started, that is, when the telephone line is not used, the process returns to step S1 to calculate a new current position and detect a moving speed. When communication with the information center 4 is started, that is, when a telephone line is used, the process proceeds to step S4, and it is determined whether or not the moving speed detected in step S2 is equal to or higher than a predetermined speed. The predetermined speed is PH
This is the maximum traveling speed that the S line can use, and is set to, for example, 20 km / h. For example, when the vehicle 5 is traveling on a highway, the moving speed is equal to or higher than a predetermined speed, so that the communication line switching device 21 is controlled to cause the mobile phone 22 to transmit the telephone number of the information center 4 (step S5). ). Further, for example, when the vehicle 5 is stopped waiting for a traffic light or is running slowly due to traffic congestion, it is determined that the moving speed is lower than the predetermined speed, and the PHS telephone 23 calls the information center 4 The number is transmitted (step S6).

When connected to the information center 4 via a portable telephone line or a PHS telephone line, the current position data of the vehicle 5 is transmitted to the information center 4 (step S7).
When the information center 4 receives all the current position data transmitted from the vehicle 5, it returns road map information, traffic information, weather forecast information, and the like near the current position of the vehicle 5 through the currently connected communication line. .

When the road map information and the like returned from the information center 4 are received (step S8), the received information is stored in the reception information holding unit 17 (step S9). When all the information transmitted from the information center 4 is stored in the reception information holding unit 17 (step S10), the communication with the information center 4 is terminated (step S11). And CPU
13 sequentially reads the road map information and the like stored in the reception information holding unit 17 and further controls the display control unit 15 to display the contents on the display 16 (step S12).

The above steps S1 to S12
Is automatically performed every time the vehicle 5 moves a predetermined distance. Therefore, a road map and the like can be displayed on the display 16 in accordance with the movement of the vehicle 5, and the latest traffic information and the like can always be displayed. It is not always necessary to automatically connect the communication line to the information center 4. When a driver or a passenger pushes an information request key (not shown), the line is connected to the information center 4. Is also good. If the communication line is interrupted during the communication, the processing is performed again from step S1.

As described above, the moving speed of the vehicle 5 when receiving information from the information center 4 is detected, and when the moving speed is lower than a predetermined speed (for example, 20 km / h), the information center is connected via the PHS line. 4, the time required for data transmission is reduced. Also, P
Since the call rate of the HS line is lower than the call rate of the mobile phone line, the cost for data communication is reduced. When the moving speed is equal to or higher than the predetermined speed, information is provided from the information center 4 via the mobile phone line, so that data transmission is not disabled due to the high-speed movement of the vehicle 5. In this way, various data can be transmitted efficiently.

If it is determined in step S3 that the vehicle 5 is moving slowly or stopped, and the PHS line is used, the vehicle 5 accelerates during communication and the moving speed of the vehicle 5 becomes higher than a predetermined speed. there is a possibility. However, the amount of data transmitted from the information center in one communication is usually 150
Since the time required for data transmission is about 5 seconds when using a PHS line of about kbytes and a line speed of 32 kbps, there is little possibility that the speed of the vehicle will fluctuate significantly during this time. No problem.

If the data amount is very large, P
It is also conceivable to acquire data using an HS line, disconnect the PHS line when the speed exceeds 20 km / h or go out of the PHS cell, and re-call the mobile phone to acquire the remaining data. FIG. 4 is a block diagram showing an electrical configuration of the data communication device according to the second embodiment of the present invention.
In the above description of the first embodiment, the configuration in which the data communication device according to the present invention is connected to the navigation device and obtains road map information, traffic information, and the like has been described. A configuration for connecting to a personal computer or the like to perform personal computer data communication or the like in a moving body such as a vehicle will be described. FIG.
, Parts having the same functions as the respective parts shown in FIG. 1 are denoted by the same reference numerals.

The data communication device 20A of the second embodiment
Has a CPU 30 in addition to the components of the data communication device 20 of the first embodiment described above.
Accordingly, the communication line switching device 21 is controlled. Specifically, the vehicle speed sensor 14 is connected to the CPU 30,
CPU 30 determines which of mobile phone 22 and PHS phone 23 to use based on the output of vehicle speed sensor 14 and controls communication line switching device 21. Also, C
The PU 30 is connected to the personal computer 40, receives data to be transmitted to the communication device outside the mobile body (hereinafter, referred to as “transmission data”) from the personal computer 40, and receives data from the communication device outside the mobile body. Data (hereinafter, referred to as “received data”) is provided to the personal computer 40.

Next, the control operation of the CPU 30 will be described in detail. When a keyboard (not shown) connected to the personal computer 40 is operated by the user,
When a signal indicating that transmission data is to be transmitted is input to CPU 30, CPU 30 detects the moving speed of the moving object based on the output of vehicle speed sensor 14. Then, the CPU 30
The detected moving speed is a predetermined speed (for example, 20 km / h)
If the moving speed is equal to or higher than the predetermined speed, the communication line switching device 21 is controlled to transmit the transmission data from the mobile phone 22 to the transmission destination. When the moving speed is lower than the predetermined speed, the communication line switching device 21 is controlled to transmit the transmission data from the PHS telephone 23 to the transmission destination.

As described above, when the moving speed is equal to or higher than the predetermined speed, the transmission data is transmitted via the mobile phone line,
When the moving speed is lower than the predetermined speed, the transmission data is transmitted via the PHS line, so that the same operation and effect as those of the data communication device of the first embodiment can be obtained. When data is received from a communication device outside the moving body, the telephone number of the mobile phone 22 is dialed by the communication device, and the data is received via the mobile phone line. As a result, data can be satisfactorily received regardless of the moving speed of the moving object.

The data communication device of the second embodiment is
By connecting the facsimile apparatus to the CPU 30 via a modem or the like, facsimile communication with a facsimile apparatus or the like outside the moving body can be performed. Although the description of the embodiment of the present invention is as described above, the present invention is not limited to the above embodiment. For example, in the description of each of the above-described embodiments, a mobile phone line and a PHS line are used. However, it is needless to say that a car phone line can be used instead of the mobile phone line.

In addition, various changes can be made within the scope described in the claims.

[0041]

According to the first aspect of the present invention, the most suitable communication means can be used in accordance with the moving speed of the moving object, and the speed detecting means is connected to the navigation device. And the configuration of the device is simple. According to the second aspect of the present invention, in addition to the navigation device, it can be connected to, for example, a personal computer or a facsimile device and used when performing personal computer data communication or facsimile communication.

According to the third aspect of the present invention, based on a simple determination such as determining whether or not the moving speed of the moving body is equal to or higher than a predetermined speed, the first and second communication means are provided. The communication means that is more suitable for the moving speed at that time can be selected. According to the fourth aspect of the present invention, when the moving speed of the moving object is lower than the predetermined speed, communication with the external communication device is performed via the PHS line, so that the time required for data transmission is reduced. Also, generally speaking, the call charges for the PHS line are lower than the call charges for the mobile telephone line, so that the cost for data communication is reduced. When the moving speed is equal to or higher than the predetermined speed, communication with an external communication device is performed via the mobile phone line, so that data transmission is not disabled due to high speed movement of the moving body.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a system for providing road map information, traffic information, and the like to a vehicle equipped with a data communication device according to the present invention.

FIG. 2 is a block diagram showing an electrical configuration of a navigation device and a data communication device mounted on a vehicle.

FIG. 3 is a flowchart illustrating a flow of a control operation of a CPU.

FIG. 4 is a block diagram illustrating an electrical configuration of a data communication device according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 10 navigation device 13, 30 CPU 14 vehicle speed sensor 20, 20A data communication device 21 communication line switching device 22 mobile phone 23 PHS machine

Claims (4)

[Claims] 1. A data communication device applied to a navigation device having a speed detecting means for detecting a moving speed of a moving body, for communicating various data with a communication device outside the moving body, the data communication device comprising: A plurality of communication means capable of communicating with the communication device; and a selection means for selecting one of the plurality of communication means in accordance with a moving speed of the moving object detected by the speed detection means at the time of starting communication. A data communication device for communicating various data by using a communication means selected by the user. 2. A data communication device mounted on a mobile body for communicating various data with a communication device outside the mobile body, comprising: a plurality of communication means capable of communicating with a communication device outside the mobile body; Speed detecting means for detecting the moving speed of the moving object; and selecting means for selecting one of the plurality of communication means in accordance with the moving speed of the moving object detected by the speed detecting means at the start of communication. A data communication device for communicating various data by using a communication means selected by the user. 3. The communication means according to claim 1, wherein said plurality of communication means include a first communication means having a relatively low communication speed and a second communication means having a relatively high communication speed.
Communication means, and the selection means has a determination means for determining whether the moving speed of the moving object detected by the speed detection means at the start of communication is higher or lower than a predetermined speed. When the determining means determines that the moving speed is equal to or higher than the predetermined speed, the first communication means is selected, and when it is determined that the moving speed is lower than the predetermined speed, the second communicating means is selected. 3. The data communication apparatus according to claim 1, wherein the communication means is selected. 4. The first communication means is a portable telephone or a car telephone, and the second communication means is a PHS (Personal Handy-phone).
The data communication device according to claim 3, wherein the data communication device is a System) device.