JP2004117327A - On-vehicle navigation device and road information server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a time for downloading road information and communication expenses for a radio communication means by reducing the amount of road information to be downloaded via the radio communication means depending on a vehicle travel route. <P>SOLUTION: This on-vehicle navigation device 1 comprises a position detecting means 2 for detecting position formation for a vehicle, a road information requesting means 10 for requesting the road information for the position information to a server via the radio communication means, a display means 7 for displaying the road information received from the server 15, and a road determining means 4 for determining from the detected position information whether the vehicle is located or not on a predetermined road with no crossing. The road information requesting means 10 reduces the amount of the received road information by requesting only the road information relating to the predetermined information to the server 15 when the road determining means 4 determines that the vehicle is located on the predetermined road. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a position detecting unit that detects position information of a vehicle using a GPS, a road information requesting unit that requests road information related to the detected position information to a road information server via a wireless communication unit, A vehicle-mounted navigation device including a display unit for displaying road information received from a server; and the road information server.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an on-vehicle navigation device obtains a route to a destination input before operation based on road information stored in a DVD-ROM or a CD-ROM, displays the route on a monitor, and provides travel route guidance to the destination. To provide information on the surrounding area.
[0003]
However, road information stored on a read-only recording medium such as a DVD-ROM or a CD-ROM cannot be updated, so that the road information becomes obsolete with time. For this reason, it has been difficult for an in-vehicle navigation device that reads road information from a DVD-ROM, a CD-ROM, or the like to provide travel route guidance, and always provides travel route guidance or the like using the latest road information.
[0004]
Also, there is an in-vehicle navigation device that records road information on a readable and writable recording medium such as a hard disk drive (HDD) instead of a read-only recording medium such as a DVD-ROM or a CD-ROM to provide a travel route guidance. At present, only road information when the navigation device is sold is recorded in the HDD, and it is practically difficult to add or change the latest road information.
[0005]
Therefore, in recent years, mobile phones, PHSs (Personal Handyphone Systems), wireless LANs (HYPERLINK "http://yougo.ascii24.com/gh/08/000817.html", IEEE802.11b, HYPERLINK / hyperlink / hyperlink / hyperlink. Ascii24.com/gh/08/000817.html ”A wireless communication means such as an IEEE802.11a standard) is used to access a road information server on which the latest road information is recorded from a vehicle-mounted navigation device. An on-vehicle navigation device (hereinafter, referred to as a communication type navigation device) that acquires road information and provides travel route guidance using the latest road information has been developed (for example, see Patent Document 1). In such a communication type navigation device, not only can the latest map information be used, but also the latest information on detailed store information, traffic congestion information, accident information, congestion information on toll parking lots, etc. around the vehicle traveling position can be obtained. It is possible to do.
[0006]
[Patent Document 1]
JP-A-11-237251
[0007]
[Problems to be solved by the invention]
However, in the communication type navigation device, since it is necessary to access the road information server and download the road information, there is a problem that it takes longer to read the road information than when reading the road information recorded on a DVD-ROM or the like. In addition, there is a problem that a communication cost is separately generated because the wireless communication means is used. In particular, when the communication type navigation device sets a distant destination and collectively downloads road information necessary for route guidance from a road information server, the longer the distance to the destination, the more necessary. As a result, the amount of road information increases, which results in an increase in download time and communication cost.
[0008]
Further, when the download method of the road information in the wireless communication means is a packet charging method or the like, the road information server is connected to the road information server constantly or frequently, and the road information around the vehicle travel position is frequently updated according to the travel position of the vehicle. A method of acquiring the latest road information by updating the information has been proposed. If the amount of road information to be downloaded increases, there is a possibility that downloading of data necessary for road information display processing may not be performed in time for the display processing. .
[0009]
The present invention has been made in view of the above circumstances, and is intended to reduce the amount of road information to be downloaded via wireless communication means and download road information in accordance with the travel route of a vehicle. It is an object of the present invention to provide an on-vehicle navigation device and a road information server which can reduce the time required and the communication cost of the wireless communication means.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a road information requesting device for requesting a server via wireless communication means for a position detecting means for detecting position information of a vehicle and road information relating to the detected position information. Means and a display means for displaying the road information received from the server, whether the vehicle is located on a predetermined road having no intersection based on the position information detected by the position detection means. The road information requesting means, when the road determining means determines that the vehicle is located on the predetermined road, only the road information related to the predetermined road, It is an in-vehicle navigation device that requests a server.
[0011]
According to a second aspect of the present invention, there is provided a position detecting unit for detecting position information of a vehicle, a road information requesting unit for requesting a server via a wireless communication unit for road information relating to the detected position information, and receiving from the server Display means for displaying road information, wherein the on-vehicle navigation device receives route information from the server to the set destination, wherein the road information requesting means does not have an intersection as a route to the destination. When a predetermined road is set, the vehicle-mounted navigation device requests only the road information related to the predetermined road from the server as road information of the predetermined road portion of the road information.
[0012]
According to a third aspect of the present invention, in the on-vehicle navigation device according to the first or second aspect, the road information related to the predetermined road includes map information indicating a wide area by increasing the scale of the map. It is characterized by road information in which the amount of map information is reduced by using it as map information included in the information.
[0013]
The invention according to claim 4 is the vehicle-mounted navigation device according to claim 1 or 2, wherein the road information related to the predetermined road includes map information that does not include map information around the predetermined road. It is characterized in that it is road information in which the amount of map information is reduced by using the information as map information.
[0014]
According to a fifth aspect of the present invention, in the vehicle-mounted navigation device according to the first or second aspect, the road information relating to the predetermined road does not include any map information.
[0015]
According to a sixth aspect of the present invention, in the in-vehicle navigation device according to any one of the first to fifth aspects, a display content changing means for selecting display content of road information displayed on the display unit. Wherein the road information requesting means is capable of requesting the server for road information relating to the predetermined road when a change in display content is permitted by the display content changing means.
[0016]
The invention according to claim 7 is a road information server that transmits road information corresponding to the road information request in response to a road information request from the on-vehicle navigation device, wherein the road information server transmits the road information from the on-vehicle navigation device. When a predetermined road having no intersection is included in the route set based on the request, the road information server transmits simplified road information with a reduced amount of map information around the predetermined road.
[0017]
The invention according to claim 8 is a road information server that transmits road information corresponding to the road information request in response to a road information request from the on-vehicle navigation device. If it is determined that the vehicle is on a predetermined road that does not have an intersection based on the vehicle, the road information server transmits simple road information in which the amount of map information around the predetermined road is reduced as road information around the vehicle position. Features.
[0018]
According to a ninth aspect of the present invention, in the road information server according to the seventh or eighth aspect, the simplified road information is map information indicating a wide area by increasing the scale of the map.
[0019]
According to a tenth aspect of the present invention, in the road information server according to the seventh or eighth aspect, the simplified road information is information that does not include map information around the predetermined road.
[0020]
An invention according to claim 11 is the road information server according to claim 7 or 8, wherein the simplified road information does not include any map information.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a vehicle-mounted navigation device according to the present invention. The on-vehicle navigation device 1 includes a position detector 2 for calculating the current position of the vehicle, an azimuth detector 3 for determining the current azimuth of the vehicle, a road entrance and a road exit such as a highway or a toll road. The vehicle is located on a special road (a predetermined road without an intersection, hereinafter referred to as a predetermined road) that does not directly intersect another road at an intersection or the like from a road entrance to a road exit. A travel path detector 4 for determining whether or not the vehicle is traveling, a vehicle speed detector 5 for detecting the vehicle speed of the traveling vehicle, and a communication controller 6 for transmitting and receiving information (data) to and from a road information server 15 described later. A display unit 7 for displaying map information and the like among the received road information, an audio output unit 8 for generating audio data based on the received road information, and a driver for inputting various settings of the in-vehicle navigation device. Operation section And a control unit 10 for performing control processing based on input / output signals from each processing unit, and a memory 11 for storing necessary information. A GPS antenna 12, a vehicle speed sensor 13, and a wireless communication device (for example, (Mobile phone, PHS, wireless LAN, etc.) 14 and the like.
[0022]
A GPS antenna 12 is connected to the position detection unit 2, and the position detection unit 2 receives a GPS signal emitted by a satellite by the GPS antenna 12 and obtains position information of the vehicle.
[0023]
The azimuth detecting unit 3 detects the running azimuth of the vehicle by detecting a change in the running position of the vehicle detected by the position detecting unit 2 and an azimuth change in the running state obtained by using a gyro. The vehicle speed detection unit 5 obtains a vehicle speed pulse from the vehicle speed sensor 13 of the vehicle body and obtains a running speed of the vehicle.
[0024]
The traveling path detector 4 determines whether the vehicle is traveling on a predetermined road. For example, it is determined whether the vehicle is traveling on a highway or whether it is traveling on a general road such as a national road or a prefectural road. Various methods and techniques are known as specific determination methods, and the present invention is not limited to a specific method or technique.
[0025]
For example, today, with the spread of VICS (road traffic information communication system), a large number of antennas for transmitting VICS traffic information are installed in urban areas and major arterial roads. As a VICS antenna, a radio beacon is used on an ordinary road and an optical beacon is used on an expressway. Therefore, whether traffic information received by a vehicle is traffic information emitted from the optical beacon or whether a radio beacon is used. By determining whether or not the traffic information is issued, it is possible to determine whether the vehicle is traveling on a predetermined road or a general road (Japanese Patent Application Laid-Open No. H8-189956). Gazette).
[0026]
In addition, many ETCs (automatic toll collection systems) have been introduced on toll roads today, and when a vehicle enters a toll road, a signal received from a roadside machine at the ETC gate is used to determine whether to enter or leave the toll road. However, it is possible to determine whether the vehicle is traveling on a predetermined road or a general road (see Japanese Patent Application Laid-Open No. 2001-202009).
[0027]
Further, when the predetermined road is an elevated road and the traveling position of the vehicle is higher than a general road, the predetermined road is determined by obtaining the height of the vehicle position detected by the position detection unit 2. It is possible to determine whether the vehicle is traveling or on a general road.
[0028]
The operation unit 9 is an operation device including a controller, a touch panel, and the like, and is used when a driver or the like performs various settings on the in-vehicle navigation device (for example, various settings for providing destination information and route guidance (no sound output). , Setting without monitor display, etc.), the setting is input by operating the operation unit 9.
[0029]
The audio output unit 8 is a speaker that outputs audio data in response to a command from the control unit 10 described below, and the display unit 7 displays information visually represented as road information, such as map information. Monitor.
[0030]
The communication control unit 6 is connected to the wireless communication device 14, and transmits and receives information between the vehicle-mounted navigation device 1 and the road information server 15 by connecting a communication line to the road information server 15 using the wireless communication device 14. Is possible. Although the wireless communication device 14 is shown separately from the in-vehicle navigation device 1 in FIG. 1, the wireless communication device 14 may be installed so as to be integrated in the in-vehicle navigation device 1. The memory 11 temporarily stores road information and the like received from the road information server 15 via the communication control unit 6.
[0031]
The control unit 10 includes a CPU and peripheral circuits (RAM, ROM, and the like) necessary for control processing by the CPU, and detects the position of the vehicle detected by the position detection unit 2 and the position of the vehicle detected by the direction detection unit 3. Based on the traveling azimuth, the traveling speed of the vehicle detected by the vehicle speed detection unit 5, the traveling route information of the vehicle detected by the traveling route detection unit 4, and the setting information input from the operation unit 9, the travel route guidance is required. The road information is determined, and a road information request command is transmitted to the road information server via the communication control unit 6 to request necessary road information. Further, the control unit 10 outputs the road information acquired via the communication control unit 6 to the display unit 7 and outputs audio information from the audio output unit 8 as necessary. Detailed control processing by the control unit 10 will be described later using a flowchart.
[0032]
FIG. 2 is a block diagram illustrating a connection relationship between the vehicle-mounted navigation device 1 and the road information server 15. The road information server 15 includes a router 16, an input / output control unit 17, and a road information database 18, and can transmit and receive information to and from the vehicle-mounted navigation device 1 via a network and a base station 19. Has become.
[0033]
The road information database 18 records nationwide road information, for example, nationwide map information, address information, store information, expressway service area names, parking area names, interchange names, and respective distance information for each scale. It is updated to the latest information at regular intervals (for example, one month). Further, the road information database 18 further records weather information, temperature information, accident information, road regulation information, and the like for each area, and these information are spaced more closely than the map information and the like (for example, 30). Updated every minute).
[0034]
The router 16 checks the data contents transmitted to the road information server 15 via the network, and determines whether to permit input / output of data to / from the road information server 15.
[0035]
The input / output control unit 17 analyzes the content of the transmitted data, determines the road information requested by the on-vehicle navigation device 1, extracts necessary data from the road information database 18, and outputs the requested data via the router 16. The road information is transmitted to the in-vehicle navigation device 1.
[0036]
In FIG. 2, the road information server 15 is configured to transmit and receive information to and from the on-vehicle navigation device 1 via a network. The network may be a network in which the devices are connected one-to-one by peer-to-peer connection, or a LAN-type network in which network connection is permitted only within a certain range (only a specific in-vehicle navigation device). A wide open network may be used.
[0037]
Hereinafter, the flow of the road information acquisition process in the control unit 10 of the vehicle-mounted navigation device 1 will be described using a flowchart. FIG. 3 is a flowchart showing a process in which the in-vehicle navigation device 1 collectively downloads road information to the destination from the road information server 15 and stores it in the memory 11 after the driver sets the destination. is there.
[0038]
First, a destination setting process is performed by the driver (step S1). Specifically, the driver sets the destination in the vehicle-mounted navigation device 1 by operating the operation unit 9 and inputting the address, telephone number and the like of the destination. At this time, the driver can set “Expressway mode” as the type of image information to be displayed on the display unit 7. Mode "can be set. The set destination and display mode are stored in the memory 11.
[0039]
Here, the expressway mode is a display mode in which map information around a predetermined road is not displayed as road information when the vehicle travels on the predetermined road. For example, when driving on a highway, information on the city area around the highway (for example, one-way information in the city area) is not always necessary, and information on the highway (specifically, minimum map information on the highway) is required. , Expressway entrance / exit information (interchange name, remaining distance, interchange closure information, etc.), junction (junction) information, service area, parking area information, expressway traffic congestion information and danger information (accidents, falling objects, If information such as strong wind, rain, etc.) is displayed, there is no problem in running. For this reason, only information on a predetermined road that does not hinder traveling is requested to the road information server 15.
[0040]
The simple display mode is a display mode in which simple map information around a predetermined road is displayed on the display unit 7 in addition to only information about a predetermined road that does not hinder traveling. The simple map information is By setting the scale of the map to be large so that the wide area can be displayed roughly (wide area map display), or by displaying only the main roads (national roads and prefectural roads), the amount of road information can be reduced more than ordinary map information. This is the reduced map information.
[0041]
In order to correspond to these display modes, the road information database of the road information server 15 stores two types of road information (road information corresponding to the expressway mode and road information corresponding to the simple display mode) as road information on the predetermined road. ) Is recorded, and the runway information server 15 can transmit either one of the road information in response to a request from the in-vehicle navigation device.
[0042]
Next, the control unit 10 determines whether or not to use a predetermined road in a route (guide route) used for guiding the vehicle to the set destination on the traveling route (step S2). When the predetermined road is not used (in the case of NO in step S2), the control unit 10 requests the road information server 15 to transmit road information including normal map information from the current position or a predetermined departure point to the destination. The transmission data including the request data and the data on the current position or the predetermined departure point and the destination position is created (step S3).
[0043]
When the predetermined road is used in the route to the destination (YES in step S2), control unit 10 determines whether or not the expressway mode is set as the display mode (step S4). If the expressway mode is not set (NO in step S4), the control unit 10 sends request data for requesting road information including normal map information from the current position or a predetermined departure point to a destination. The transmission data including the data on the current position or the predetermined departure point and the destination position is created (step S3).
[0044]
When the expressway mode is set as the display mode (YES in step S4), control unit 10 further determines whether or not the simple display mode is set (step S5). If the simple display mode has not been set (NO in step S5), the control unit 10 requests the road information including the map information corresponding to the expressway mode and the current position or the predetermined departure point. , And transmission data including data relating to the target position (step S6). If the simple display mode is set (YES in step S5), the control unit 10 requests the road information including the map information corresponding to the simple display mode and the current position or the predetermined departure point. , And transmission data including data relating to the target position (step S7).
[0045]
After creating the transmission data to be transmitted to the road information server 15 by the above-described processing, the control unit 10 transmits the transmission data from the communication control unit 6 to the road information server 15 via the wireless communication device 14, and A process of collectively downloading information is performed, and the downloaded road information is recorded in the memory 11 (step S8).
[0046]
FIG. 4 shows a state after the batch download processing of the road information shown in FIG. 3 and the control unit 10 stores in the memory 11 in accordance with the traveling position of the vehicle from the start of traveling until the vehicle arrives at the destination. 5 is a flowchart illustrating a process of reading map information and the like around a traveling position and displaying the map information on a display unit 7.
[0047]
First, the control unit 10 determines whether or not the vehicle has arrived at the destination based on the position information detected by the position detection unit 2 (Step S11). If the vehicle has not yet arrived at the destination (NO in step S11), control unit 10 determines whether the vehicle is currently traveling on a predetermined road (step S12). When the vehicle is not traveling on the predetermined road (NO in step S12), control unit 10 executes normal guidance processing (general traveling processing) for displaying ordinary map information on display unit 7 and performing traveling route guidance. (Step S13).
[0048]
When the vehicle is traveling on a predetermined road (in the case of YES in step S12), the control unit 10 determines whether or not the expressway mode is stored in the memory 11 as the display mode, that is, the driver sets the expressway mode. It is determined whether or not it has been performed (step S14). If the highway mode has not been set (NO in step S14), the control unit 10 executes a normal guidance process (general traveling process) (step S13).
[0049]
If the highway mode is set as the display mode (YES in step S14), the control unit 10 further determines in the memory 11 whether the simple display mode has been set. It is determined based on whether or not it is stored (step S15). If the simple display mode has been set (YES in step S15), the image data is changed so that the map information with the scale of the map enlarged is displayed on the display unit (step S16), and the simple display mode is set. Is not set (NO in step S15), the display unit 7 displays only information on a predetermined road (for example, an expressway) so that map information around the predetermined road is not displayed on the display unit 7. The image data corresponding to the changed display mode is displayed on the display unit 7 (step S17), and the control unit 10 performs travel route guidance (step S18).
[0050]
The traveling route guidance processing based on this display mode (step S18) is repeated while the vehicle is traveling on the predetermined road (in the case of YES in step S19), and the control unit 10 determines that the vehicle is not traveling on the predetermined road. When it is determined (NO in step S19), the control unit 10 executes a normal guidance process (general traveling process) for displaying the ordinary map information on the display unit 7 to provide a traveling route guidance (step S13). It is determined again whether the vehicle has arrived at the destination (step S11). If the vehicle has not arrived at the destination (NO in step S11), the above-described process (step S12) is repeated again, and if the vehicle has arrived at the destination (YES in step S11). The control unit 10 ends the traveling route guidance processing.
[0051]
As described above, when the vehicle is traveling on a predetermined road, the map information to be displayed on the display unit 7 is omitted or the scale is changed to simplify the map information. The amount can be reduced, and the download time and communication cost can be reduced.
[0052]
The processing of the control unit 10 when the in-vehicle navigation device 1 collectively downloads the road information to the destination from the road information server 15 has been described with reference to the flowcharts illustrated in FIGS. 3 and 4. However, the present invention is not limited to the case where the vehicle-mounted navigation device 1 collectively downloads road information. For example, based on the position detection unit 2, the azimuth detection unit 3, and the vehicle speed detection unit 5, the control unit 10 constantly determines the content of map information and the like to be displayed on the display unit 7, and determines the travel position of the vehicle based on the travel position. A method may be used in which a certain range of road information that is sometimes required is downloaded little by little and frequently from a road information server.
[0053]
FIG. 5 is a flowchart illustrating a process of the control unit 10 when the road information is frequently downloaded from the road information server 15 according to the traveling position of the vehicle.
[0054]
After the destination setting process is performed by the driver (step S21), the control unit 10 determines whether the vehicle has arrived at the destination by using the position detection unit 2 (step S22). If the vehicle has not yet arrived at the destination (NO in step S22), control unit 10 determines whether the vehicle is traveling on a predetermined road (step S23). When the control unit 10 determines that the vehicle is not traveling on the predetermined road (NO in step S23), the control unit 10 sets a minimum necessary range (narrow range) of road information including normal map information. Is determined, and the road information in the determined range is downloaded from the road information server 15 with reference to the position detection unit 2, the direction detection unit 3, and the vehicle speed detection unit 5. After that, the control unit 10 performs travel route guidance using the downloaded road information (step S24).
[0055]
When the control unit 10 determines that the vehicle is not traveling on the predetermined road (YES in step S23), the control unit 10 determines whether the highway mode is set in the display mode (step S23). S25). If the expressway mode has not been set as the display mode (NO in step S25), the control unit 10 transmits the road information server including the ordinary map information to the road information server in the minimum necessary range (narrow range). , And provides travel route guidance using the downloaded road information (step S24).
[0056]
When the expressway mode is set as the display mode (in the case of YES in step S25), the control unit 10 further determines whether or not the simple display mode is set (step S26). If the simple display mode is set (YES in step S26), the control unit 10 transmits the road information server including the road information including the map information in the simple display mode to the minimum necessary range (narrow range). 15 and the travel route guidance is performed using the downloaded road information (step S27). If the simple display mode has not been set (NO in step S26), the control unit 10 transmits the road information including the map information in the expressway mode to the minimum required range (narrow range). The route is downloaded from the server 15 and travel route guidance is performed using the downloaded road information (step S28).
[0057]
Thereafter, the control unit 10 determines whether or not the vehicle is traveling on a predetermined road (step S29). If the vehicle is traveling on a predetermined road (YES in step S29), the display mode is set. The determination process (step S25) for determining whether or not the highway mode has been set is repeated. When it is determined that the vehicle is not traveling on the predetermined road (NO in step S29), the control unit 10 transmits the road information including the normal map information to the road information server in a minimum necessary range (narrow range). 15 and the travel route guidance is performed using the downloaded road information (step S24). Thereafter, it is determined again whether the vehicle has arrived at the destination (step S22). If the vehicle has not arrived at the destination (NO in step S22), the vehicle travels on a predetermined road. A determination process is performed as to whether or not there is (step S23). If the vehicle has arrived at the destination (YES in step S22), control unit 10 ends the process.
[0058]
As described above, even when the required road information is obtained from the traveling position of the vehicle or the like and the control method of frequently downloading the minimum road information from the road information server is used, the display mode is the highway mode, When the display mode is set, the amount of information to be downloaded can be reduced as compared with ordinary road information, so that download time and communication cost can be reduced.
[0059]
The configurations of the vehicle-mounted navigation device and the road information server according to the present invention are not limited to those described above. For example, a configuration may be adopted in which the driver sets one of three display modes in advance, namely, a normal mode, an expressway mode, and a simple display mode, or only the expressway mode or the simple display mode is set. You may be able to. Further, when the control unit 10 determines that the vehicle is traveling on a predetermined road without allowing the driver to set the display mode, or that the control unit 10 determines that the predetermined road is included in the set route, Alternatively, road information including map information in the expressway mode or the simple display mode may be downloaded from the road information server.
[0060]
In the description of the above embodiment, it is determined in the on-vehicle navigation device whether the vehicle is on a predetermined road, or whether the predetermined road is included in the route set based on the information of the current location (departure location) and the destination. Although the determination is made, the above determination may be made by the road information server, and the content (type) of the road information transmitted to the in-vehicle navigation device may be changed based on the determination result.
[0061]
【The invention's effect】
As described above, according to the on-vehicle navigation device and the road information server according to the present invention, the time required for downloading the road information and the wireless communication means are lower than when ordinary road information is downloaded from the road information server. Communication costs can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an in-vehicle navigation device according to the present invention.
FIG. 2 is a block diagram showing a connection relationship between a vehicle-mounted navigation device and a road information server according to the present invention.
FIG. 3 is a flowchart showing a batch download process of road information by a control unit of the vehicle-mounted navigation device according to the present invention.
FIG. 4 is a flowchart showing a process of a control unit for performing route guidance by displaying road information on a display unit when the vehicle is running after performing the process according to the flowchart shown in FIG. 3;
FIG. 5 is a flowchart showing a process of frequently downloading road information by a control unit of the vehicle-mounted navigation device according to the present invention.
[Explanation of symbols]
1 In-vehicle navigation device
2 Position detector (position detector)
3 Direction detector
4 Running path detector (road determination means)
5 Vehicle speed detector
6 Communication control unit
7 Display part (display means)
8 Audio output section
9 Operation section
10 control unit (road information request means)
11 memory
12 GPS antenna
15 road information server (server)
16 router
17 I / O controller
18 road information database
19 base station

Claims (11)

Position detecting means for detecting the position information of the vehicle, road information requesting means for requesting the road information on the detected position information to the server via the wireless communication means, and display means for displaying the road information received from the server; In the in-vehicle navigation device equipped with
Road judgment means for judging whether or not the vehicle is located on a predetermined road having no intersection based on the position information detected by the position detection means,
Wherein the road information requesting unit requests only the road information related to the predetermined road from the server when the road determining unit determines that the vehicle is located on the predetermined road. Navigation device. Position detecting means for detecting the position information of the vehicle, road information requesting means for requesting the road information on the detected position information to the server via the wireless communication means, and display means for displaying the road information received from the server; In the in-vehicle navigation device that receives the route information to the set destination from the server,
When a predetermined road having no intersection is set as a route to the destination, only the road information related to the predetermined road is included in the road information as the road information of the predetermined road portion. Request from the server. The road information related to the predetermined road is road information in which the amount of map information is reduced by using map information indicating a wide area by increasing the scale of the map as map information included in the road information. The in-vehicle navigation device according to claim 1 or 2, wherein: The road information related to the predetermined road is road information in which the amount of map information is reduced by using map information that does not include map information around the predetermined road as map information included in the road information. An in-vehicle navigation device according to claim 1 or 2. The on-vehicle navigation device according to claim 1 or 2, wherein the road information related to the predetermined road does not include any map information. A display content changing unit for selecting display content of road information displayed on the display unit,
The said road information request means can request | require the said server the road information relevant to the said predetermined road from the said server, when the change of the display content is permitted by the said display content change means. An in-vehicle navigation device according to claim 5. A road information server that transmits road information corresponding to the road information request in response to a road information request from the vehicle-mounted navigation device,
When a predetermined road having no intersection is included in the route set based on the road information request from the on-vehicle navigation device, simple road information with a reduced amount of map information around the predetermined road is transmitted. Road information server. A road information server that transmits road information corresponding to the road information request in response to a road information request from the vehicle-mounted navigation device,
When it is determined that the vehicle is on a predetermined road having no intersection based on the position information from the on-vehicle navigation device, simple road information in which the amount of map information around the predetermined road is reduced as road information around the vehicle position A road information server, which transmits 9. The road information server according to claim 7, wherein the simplified road information is map information indicating a wide area by increasing the scale of the map. The road information server according to claim 7, wherein the simplified road information is information that does not include map information around the predetermined road. 9. The road information server according to claim 7, wherein the simplified road information does not include any map information.

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