JP5734616B2 - Car navigation system and traffic information tuning method - Google Patents

Description

  The present invention relates to an in-vehicle navigation apparatus and a traffic information channel selection method for selecting a broadcast station that broadcasts traffic information.

  A conventional typical vehicle-mounted navigation device includes a control device such as a CPU for controlling all processing related to navigation, and a storage device such as a DVD (Digital Versatile Disk) -ROM or an IC memory card in which map data is stored in advance. , A display device, a GPS (Global Positioning System) receiver, a detection device for detecting the current position and current direction of the vehicle, such as a gyro and a vehicle speed sensor. Then, the control device reads out map data including the current position of the vehicle from the storage device, displays a map image around the vehicle position on the display device screen based on the map data, and indicates the current position of the host vehicle. The vehicle position mark to be displayed is superimposed on the map image, and the map image is scrolled as the vehicle moves, or the map image is fixed on the screen and the vehicle position mark is moved, so You can see at a glance whether you are driving.

  In-vehicle navigation devices are usually equipped with a function (route guidance function) that guides a user so that the user can easily travel on the road without making a mistake. According to this route guidance function, the optimal route (typically the route with the lowest cost) that connects from the departure point (typically the current position of the vehicle) to the destination using the map data by the control device. Is automatically searched by performing simulation calculation such as horizontal search method or Dijkstra method, and the searched route is stored as a guide route, and the guide route can be distinguished from other roads on the map image while driving (For example, change the color or increase the line width), or when the vehicle approaches a predetermined distance to the intersection where the course should be changed on the guidance route, the intersection on the map image By displaying a guide map (enlarged view of the intersection, an arrow indicating the direction of travel at the intersection, the distance to the intersection, the name of the intersection, etc.) In which direction to go The user is to be able to grasp.

  Furthermore, in-vehicle navigation devices can acquire various traffic-related information from the outside via the Internet or broadcast. For example, using VICS (registered trademark) (Vehicle Information and Communication System), traffic information such as traffic jams and accidents can be obtained in real time, or data broadcasts can be received to obtain traffic information and weather information. Etc. can be acquired. Information from this VICS is sent by radio wave beacons, optical beacons, or FM multiplex broadcasting.

  Patent Document 1 describes that when an emergency broadcast of television broadcasting is supplied, information from the VICS is displayed superimposed on map information on a display.

JP 2006-235911 A

However, when disasters such as earthquakes and floods occur, facilities of broadcasting stations that broadcast FM multiplex broadcasting including VICS information such as NHK-FM broadcasting stations (NHK is a registered trademark) in each prefecture are damaged. Thus, the VICS information cannot be broadcast, and the user may not be able to acquire useful information included in the VICS information such as traffic regulations in the area where the disaster occurs and in the surrounding area.

  An object of the present invention is to provide an in-vehicle navigation device and a traffic information channel selection method that can receive traffic information such as VICS information even when a disaster occurs.

In order to solve the above-mentioned problems of the prior art, according to the basic form of the present invention, the vehicle position detection means for detecting the current position of the vehicle and reception for receiving traffic information from the first FM broadcast station Means, disaster information acquisition means for acquiring information about the disaster, determining whether or not the vehicle position is within the disaster area from the information about the disaster and the vehicle position, and the vehicle position is the disaster when in the area, through the receiving unit determines whether it can receive traffic information from the first FM broadcast station, the located at the vehicle position within the affected area, before Symbol first Control means for detecting a second FM broadcast station that transmits the traffic information different from the first FM broadcast station via the receiving means when the traffic information from the FM broadcast station cannot be received. In-vehicle navigation device There is provided.

In-vehicle navigation apparatus according to this embodiment, the control means may obtain information on the disaster through the media other than the FM broadcast.

  Moreover, in the vehicle-mounted navigation apparatus according to this aspect, when the plurality of second FM broadcast stations are detected, the control means may extract the second FM broadcast station having the strongest received electric field strength. .

  Moreover, in the vehicle-mounted navigation device according to this aspect, the control means may display all via the display means when detecting a plurality of the second FM broadcast stations.

According to another aspect of the present invention, there is provided a traffic information channel selection method in an in-vehicle navigation device that receives traffic information from a first FM broadcast station, wherein the disaster information acquisition unit acquires information about a disaster; The step of detecting the current position of the host vehicle by the host vehicle position detection means and the control means determine whether the host vehicle is in the disaster area from the information on the disaster and the current position information of the host vehicle. a step, by the control unit, the when the vehicle is in the disaster area, determining whether the can receive traffic information from the first FM broadcast station via a receiving means, said control by means when it can not receive the traffic information from the first FM broadcast station, different from the first FM broadcast station through the receiving means, first transmitting the traffic information 2 Traffic information channel selection method characterized by comprising the steps of: detecting an FM station is provided.

  Moreover, in the traffic information channel selection method according to this aspect, in the step of acquiring the information related to the disaster, the information related to the disaster may be acquired via a medium other than the FM broadcast.

  In the traffic information channel selection method according to this aspect, in the step of detecting the second FM broadcast station, the second FM with the highest received electric field strength when a plurality of the second FM broadcast stations are detected. Broadcast stations may be extracted.

  In the traffic information channel selection method according to this aspect, in the step of detecting the second FM broadcast station, when a plurality of the second FM broadcast stations are detected, all are displayed via the display means. It may be.

  According to the in-vehicle navigation device and the traffic information tuning method of the present invention, when the vehicle position is in the disaster area and traffic information from the first FM broadcasting station cannot be received due to the disaster, the receiving means is used. A second FM broadcast station different from the first FM broadcast station is detected.

  Thus, even if the user does not know that an FM broadcast station that broadcasts traffic information temporarily when a disaster occurs, the user does not know how to select a broadcast station that broadcasts traffic information. Can also receive traffic information.

It is a figure which shows the relationship between the own vehicle which drive | works a disaster area when the disaster has generate | occur | produced, and the broadcast area of the FM broadcasting station which exists around the own vehicle. It is a block diagram which shows the structure of the vehicle-mounted navigation apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the automatic channel selection process to the broadcasting station which broadcasts VICS information temporarily at the time of a disaster occurrence. It is a figure which shows an example of the non-reception report image which notifies that the VICS information from the broadcasting station which broadcasts VICS information was not able to be received. It is a figure which shows an example of the channel selection report image which announces having selected the FM broadcasting station which broadcasts temporary VICS information. It is a figure which shows an example of the channel selection confirmation image which confirms with a user whether the channel selection to the FM broadcasting station which broadcasts temporary VICS information is possible. It is a figure which shows an example of the channel selection confirmation image which confirms to the user whether channel selection to FM broadcasting station is possible when a plurality of FM broadcasting stations that broadcast VICS information temporarily are detected.

  FIG. 1 is a diagram illustrating a relationship between a host vehicle traveling in a disaster area when a disaster occurs and a broadcast area of an FM broadcast station existing around the host vehicle.

In FIG. 1, 41 is the own vehicle. Reference numeral 42 denotes an FM broadcast station (first FM broadcast station) such as an NHK-FM broadcast station (NHK is a registered trademark) in each prefecture. Normally, VICS information is broadcast from this broadcast station. 43-45 are local community FM broadcasting stations and municipal FM disaster broadcasting stations.

  Here, as shown in FIG. 1, the FM broadcast station 42 shows a case where the facilities of the broadcast station are damaged by a disaster and the VICS information cannot be broadcast, and the broadcast area is indicated by a broken circle. Show. On the other hand, the FM broadcast stations 43 to 45 are broadcast stations (second FM broadcast stations) that temporarily broadcast VICS information instead of the FM broadcast station 42, and the broadcast areas are indicated by solid circles.

  Therefore, although the own vehicle 41 is located in the broadcast area of the FM broadcast station 42, the VICS information cannot be received even if the FM broadcast station 42 is selected. On the other hand, the own vehicle 41 is located in the broadcast area of the FM broadcast stations 43 and 44 and can receive VICS information broadcast from the FM broadcast stations 43 and 44.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings, taking as an example a situation in which the host vehicle 41 is located in the broadcast area of FM broadcast stations 42 to 44 as shown in FIG.

(Configuration of in-vehicle navigation system)
FIG. 2 is a block diagram showing the configuration of the in-vehicle navigation device 100 according to the embodiment of the present invention.

  In the figure, 1 is a DVD drive, and 1a is a storage medium in which map data and other guidance data are stored. In the present embodiment, the DVD-ROM 1a is used as a storage medium for storing such data, but a hard disk or other storage medium may be used. The map stored here is divided into longitude and latitude widths of appropriate sizes according to each scale level such as 1/1500, 1/25000, 1 / 50,000, 1/10000, etc. Roads, buildings, facilities, and other various properties included in are stored as a coordinate set of points (nodes) expressed in latitude and longitude. Map data includes (1) a road layer composed of road link data, intersection data, node data, etc., (2) a background layer for displaying roads, buildings, parks, rivers, etc. on a map image, and (3) a municipality. It consists of a character / symbol layer for displaying administrative division names such as names, road names, intersection names, characters, map symbols, and the like.

  In the road layer, the road link data supplies attribute information of each road. For each link constituting the road, the type of road (national road, highway, prefectural road, other road), hierarchization of the road network It consists of data such as the level, the number of nodes constituting the link, the road number (road name), and the width of the link connecting each node. The intersection data is a set of nodes closest to the intersection among the nodes on the link coupled to the intersection. The node data is a list of all nodes constituting the road, and includes position information for each node, information for identifying whether the node is an intersection or not, and the like.

  The DVD-ROM 1a stores broadcast station data for specifying a broadcast station. The broadcast station data includes data such as broadcast station name, call sign, location, broadcast type such as FM, AM and TV, broadcast frequency, broadcast area indicating the area where the broadcast can be received, presence / absence of broadcast of VICS information, and the like. It is out.

  Furthermore, disaster keyword data for specifying the type of disaster is stored in the DVD-ROM 1a. The disaster keyword data includes data of names of disaster types such as earthquakes, floods, and explosions.

  An operation unit 2 is provided with operation buttons and the like for operating the navigation apparatus body 10. In this embodiment, the operation unit 2 includes a remote control transmitter, and the user can also operate the navigation apparatus body 10 with the remote control transmitter at hand.

  3 is a GPS that receives GPS signals sent from a plurality of GPS satellites and generates and outputs GPS data such as longitude, latitude, PDOP (Position DOP) value and HDOP (Horizontal DOP) value of the current position of the vehicle. Indicates a receiver. Reference numeral 4 denotes a self-contained navigation sensor. The self-contained navigation sensor 4 is composed of an angle sensor such as a gyro that detects a vehicle rotation angle, and a distance sensor that generates a pulse for every predetermined traveling distance.

  Reference numeral 5 denotes a communication device such as a portable telephone connected to the navigation apparatus body 10. When a disaster occurs, disaster information is provided via a network from a service center server that provides information related to the disaster.

  Reference numeral 6 denotes a television tuner that receives a digital television broadcast via an antenna 6a. The TV tuner 6 receives a broadcast using 12 segments out of 13 segments constituting a frequency band for one channel of digital television broadcast or a one-segment broadcast using one segment depending on the state of the received radio wave. The TV tuner 6 extracts disaster information from the broadcast signal of the digital television broadcast and outputs it.

  Reference numeral 7 denotes a radio tuner that receives AM and FM radio broadcasts via an antenna 7a. When receiving the FM multiplex broadcast, the radio tuner 7 performs processing such as frequency conversion, amplification and detection on the broadcast signal to generate an FM detection signal, extracts the VICS information component from the FM detection signal, and demodulates it. Restore VICS information. Also, the received electric field strength is detected from the FM detection signal.

  Reference numeral 8 denotes a display unit such as a liquid crystal panel, and the navigation device body 10 displays a map around the current position of the vehicle on the display unit 8, a guidance route from the departure point to the destination, a vehicle position mark, and others. The guide information of is displayed. The display unit 8 is provided with a touch panel on the screen, and is configured with various buttons paired with the display content of the display screen. The touch panel serves as an input device for selecting a menu or the like indicated by these various buttons, and is a part of the operation unit 2. Reference numeral 9 denotes a speaker for providing guidance information to the user by voice.

  The navigation device body 10 is composed of the following. Reference numeral 11 denotes a buffer memory for temporarily storing map data read from the DVD-ROM 1a via the DVD drive 1.

  Reference numeral 12 denotes a control unit constituted by a microcomputer. The control unit 12 has a built-in navigation program, and calculates the current position of the vehicle based on a signal output from the GPS receiver 3 or a signal output from the self-contained navigation sensor 4 according to the program. Or the map data to be displayed is read from the DVD-ROM 1a to the buffer memory 11 via the DVD drive 1 or from the destination to the destination under the search conditions set using the map data read to the buffer memory 11. Various processes are executed such as searching for a guidance route up to.

  Reference numeral 13 denotes a map drawing unit that generates a map image using the map data read to the buffer memory 11, and reference numeral 14 denotes various menu screens (operation screens) and various marks such as a vehicle position mark and a cursor according to the operation status. The operation screen / mark generation part to be generated is shown.

  Reference numeral 15 denotes a guide route storage unit that stores the guide route searched by the control unit 12, and 16 denotes a guide route drawing unit that draws the guide route. The guidance route storage unit 15 stores all the nodes of the guidance route searched by the control unit 12 from the departure point to the destination. When displaying the map, the guide route drawing unit 16 reads the guide route information from the guide route storage unit 15 and draws the guide route with a color and line width different from those of other roads.

  Reference numeral 17 denotes a storage unit composed of a memory such as an EEPROM connected to the control unit 12, and stores data for specifying a broadcast station that has become an FM broadcast station that broadcasts VICS information temporarily.

  Reference numeral 18 denotes an audio output unit, which outputs an audio signal to the speaker 9 based on a signal from the control unit 12. Reference numeral 19 denotes an image composition unit, on which a map image drawn by the map drawing unit 13 is overlaid with various marks and operation screens generated by the operation screen / mark generation unit 14, a guidance route drawn by the guidance route drawing unit 16, and the like. And output to the display unit 8.

  In the in-vehicle navigation device 100 configured as described above, as a basic operation, the control unit 12 is based on the GPS signal received by the GPS receiver 3 and the signal input from the autonomous navigation sensor 4. Detect current position. Then, map data around the vehicle is read from the DVD-ROM 1 a via the DVD drive 1 and stored in the buffer memory 11. The map drawing unit 13 generates a map image based on the map data read to the buffer memory 11 and displays a map image around the host vehicle on the screen of the display unit 8 via the image composition unit 19.

  Moreover, the control part 12 detects the present position of the own vehicle based on each signal input from the GPS receiver 3 and the self-contained navigation sensor 4 with the movement of the own vehicle, and according to the detection result, the display part 8 The vehicle position mark is superimposed on the map image displayed on the screen, and the vehicle position mark is moved with the movement of the host vehicle, or the map image is scrolled.

  Further, when the user operates the operation unit 2 to set a destination and other necessary information (information about a waypoint on the way to the destination, etc.), the control unit 12 reads from the GPS receiver 3 and the autonomous navigation sensor 4. The current position of the vehicle detected based on each of the signals is used as a starting point, and a route with the lowest traffic cost from the starting point to the destination is searched using the map data of the DVD-ROM 1a. Then, the route obtained by the search is stored in the guidance route storage unit 15 as a guidance route, and the guidance route is superimposed on the map image on the screen on the display unit 8 via the guidance route drawing unit 16 and the image composition unit 19. Display together.

  As described below, the control unit 12 selects a broadcasting station that broadcasts VICS information temporarily when a disaster occurs.

(Channel selection method for broadcast stations that broadcast VICS information temporarily)
Hereinafter, automatic channel selection processing for a broadcasting station that broadcasts VICS information temporarily in the event of a disaster will be described with reference to FIGS.

  FIG. 3 is a flowchart illustrating an example of automatic channel selection processing performed by the control unit 12 of the in-vehicle navigation device 100 for a broadcasting station that broadcasts VICS information temporarily when a disaster occurs.

  First, disaster information is acquired in step S11. Disaster information is acquired via media other than FM broadcasts. For example, it is obtained by extracting from a digital television broadcast obtained via the Internet and the communication device 5 or received via the TV tuner 6.

  The disaster information includes information such as the type of disaster and the name of the disaster occurrence area. For example, the information includes the content of “an earthquake of seismic intensity 6 occurs in Iwaki City”. The data format of the disaster information is character or voice text data or binary data.

  In the next step S12, the disaster occurrence area and the adjacent area are specified as the disaster area. Specifically, the disaster occurrence area that matches the disaster type registered in the disaster keyword data of the DVD-ROM 1a is extracted from the disaster information acquired through the communication device 5 or the TV tuner 6. Next, an area adjacent to the disaster occurrence area is extracted from the map data of the DVD-ROM 1a. Identify these disaster-affected areas and their adjacent areas as affected areas.

  For example, if “Iwaki City” is a disaster occurrence area, “Iwaki City” and “city adjacent to Iwaki City” are specified as the affected areas.

  In the next step S13, the current position of the host vehicle is detected. The current position of the host vehicle is detected based on a GPS signal acquired via the GPS receiver 3 or a signal from the autonomous navigation sensor 4.

  In the next step S14, based on the map data of the DVD-ROM 1a, it is determined whether or not the vehicle position is in the disaster area. If the own vehicle position is not within the affected area, the process ends. If the own vehicle position is within the affected area, the process proceeds to step S15.

  In the next step S15, the broadcast frequency of the FM broadcast station (first FM broadcast station) that broadcasts the VICS information and uses the vehicle position as the broadcast area is extracted from the broadcast station data of the DVD-ROM 1a, and the radio A tuner 7 selects the channel.

  In the next step S16, it is determined whether or not the VICS information from the FM broadcast station selected in step S15 has been received. If the VICS information can be received, the process ends. If the VICS information cannot be received, the process proceeds to step S17.

  In the next step S <b> 17, the non-reception report image 30 informing that the VICS information has not been received is displayed on the display unit 8. In this non-reception report image 30, as shown in FIG. 4, a message indicating that the VICS information from the FM broadcasting station that broadcasts the VICS information with the vehicle position as the broadcast area could not be received, and the VICS information are broadcast. And a message to search for another FM broadcast station to be displayed.

  In the next step S18, the reception frequency is changed in the frequency band of FM broadcasting in order to search for another FM broadcasting station that broadcasts VICS information. For example, the reception frequency is increased by 100 kHz.

  In the next step S19, it is determined whether or not another FM broadcast station that broadcasts the VICS information has been detected. If another FM broadcast station that broadcasts the VICS information cannot be detected, the process proceeds to step S26, and if another FM broadcast station can be detected, the process proceeds to step S20.

  In the next step S20, the FM broadcast station detected in step S19 becomes an FM broadcast station (second FM broadcast station) that temporarily broadcasts the VICS information, and data specifying this FM broadcast station is stored in the storage unit 17. . The data specifying the FM broadcast station includes a call sign of the FM broadcast station, a broadcast frequency, and the like.

  In the next step S21, it is determined whether or not another FM broadcast station that broadcasts VICS information in the entire FM broadcast frequency band has been searched. If the entire frequency band of FM broadcasting is not searched, the process returns to step S18 to further increase the reception frequency. If the entire frequency band of the FM broadcast is searched, the process proceeds to step S22.

  In the next step S22, the broadcast frequency of the FM broadcast station that broadcasts the VICS information temporarily is extracted from the data stored in the storage unit 17, and the radio tuner 7 selects the channel.

  Further, a channel selection report image 50 for notifying that an FM broadcasting station that broadcasts VICS information temporarily is selected is displayed on the display unit 8. In this channel selection report image 50, as shown in FIG. 5, a message indicating that an FM broadcast station that temporarily broadcasts VICS information is detected, the name and broadcast frequency of the FM broadcast station, and the FM broadcast station are selected. Message is displayed.

  Thereafter, VICS information broadcast at a predetermined interval (for example, 2 minutes) is received from an FM broadcast station that temporarily broadcasts VICS information.

  On the other hand, if another FM broadcast station that broadcasts the VICS information cannot be detected in step S19, the process proceeds to step S26.

  In step S26, it is determined whether or not another FM broadcast station that broadcasts VICS information has been searched in the entire frequency band of the FM broadcast. If the entire frequency band of FM broadcasting is searched, this processing ends. If the entire frequency band of FM broadcasting is not searched, the process returns to step S18 to further increase the reception frequency.

  As described above, according to the in-vehicle navigation device 100 of this embodiment and the method of selecting a broadcasting station that broadcasts VICS information, the FM vehicle that is in the disaster area and registered in the broadcasting station data. Of the broadcasting stations, when the VICS information is broadcast and the VICS information from the FM broadcasting station having the vehicle position as the broadcasting area cannot be received, the FM broadcasting station that temporarily broadcasts the VICS information is selected.

  Thus, even if the user does not know that a broadcasting station that broadcasts VICS information temporarily when a disaster occurs, and the user does not know the channel selection method of the broadcasting station that broadcasts VICS information. VICS information can be received.

  According to the present embodiment, the FM broadcast station that broadcasts the temporary VICS information existing in the frequency band of the FM broadcast is detected by repeatedly performing the processes from step S18 to step S21. When a plurality of FM broadcast stations that temporarily broadcast VICS information are detected as in the position situation of the host vehicle 41 illustrated in FIG. 1, the FM broadcast station having the highest received electric field strength among the detected FM broadcast stations. May be selected and selected.

  In the above description, the FM broadcast station that broadcasts the VICS information temporarily is automatically selected. However, the user may select whether or not to select the FM broadcast station. FIG. 6 is a channel selection confirmation image 60 that allows the user to select whether or not to select an FM broadcast station that broadcasts VICS information temporarily. In this channel selection confirmation image 60, a message indicating that an FM broadcast station that broadcasts temporary VICS information has been detected, the name and broadcast frequency of the FM broadcast station, and whether or not to select an FM broadcast station are displayed to the user. A message for confirmation and a “Yes” button 61 and a “No” button 62 for instructing whether or not to select an FM broadcast station are displayed.

  FIG. 7 is a channel selection confirmation image 70 that allows the user to select whether or not to select an FM broadcast station when a plurality of FM broadcast stations that temporarily broadcast VICS information are detected. The channel selection confirmation image 70 includes a message that an FM broadcast station that broadcasts temporary VICS information is detected, a message that confirms whether or not to select an FM broadcast station, and an FM broadcast station. Channel selection instruction buttons 71 and 72 for instructing channel selection and a non-channel selection instruction button 73 for instructing not to select an FM broadcast station are displayed. On the channel selection instruction buttons 71 and 72, the names and broadcast frequencies of all detected FM broadcast stations are displayed.

  In the above description, the disaster area is specified based on the disaster information acquired via the communication device 5 or the TV tuner 6, but not limited thereto, for example, based on the place name input by the user via the touch panel. You may make it identify a disaster area.

100: In-vehicle navigation device,
1a ... DVD-ROM,
2 ... operation part,
3 ... GPS receiver,
4 ... Self-contained navigation sensor,
5 ... Communicator,
6 ... TV tuner,
7 ... Radio tuner,
8 ... display part,
12 ... control unit,
17 ... storage part,
30 ... non-reception report image,
41 ... Own vehicle,
42. First FM broadcast station,
43-45 ... The second FM broadcast station,
50 ... Channel report image,
60, 70 ... tuning confirmation image,
61 ... "Yes" button,
62 ... "No" button,
71, 72 ... Channel selection instruction buttons,
73: Non-tuning instruction button.

Claims (10)

Own vehicle position detecting means for detecting the current position of the own vehicle;
Receiving means for receiving traffic information from the first FM broadcast station;
Disaster information acquisition means for acquiring information about disaster;
It is determined whether or not the vehicle position is in the disaster area from the information on the disaster and the vehicle position, and when the vehicle position is in the disaster area, Determining whether or not the traffic information from one FM broadcast station can be received, and when the vehicle position is in the affected area and the traffic information from the first FM broadcast station cannot be received, the receiving means Control means for detecting a second FM broadcast station that transmits the traffic information different from the first FM broadcast station via
A vehicle-mounted navigation device comprising:   The in-vehicle navigation device according to claim 1, wherein the control unit acquires information related to the disaster through a medium other than FM broadcast.   2. The in-vehicle navigation device according to claim 1, wherein when the plurality of second FM broadcast stations are detected, the control unit extracts the second FM broadcast station having the highest received electric field strength.   The in-vehicle navigation apparatus according to claim 1, wherein the control means displays all of the second FM broadcast stations via a display means when a plurality of the second FM broadcast stations are detected. The first FM broadcasting station is a NHK-FM broadcasting station (NHK is a registered trademark) of each prefecture, and the second FM broadcasting station is a community broadcasting station in a region or a disaster broadcasting station in a municipality. The in-vehicle navigation device according to claim 1. A traffic information tuning method in an in-vehicle navigation device for receiving traffic information from a first FM broadcast station,
Acquiring disaster-related information by means of disaster information acquisition;
Detecting the current position of the host vehicle by the host vehicle position detecting means;
Determining by the control means whether or not the host vehicle is in a disaster area from information on the disaster and current position information of the host vehicle;
Determining whether the control means can receive traffic information from the first FM broadcast station via a receiving means when the host vehicle is in a disaster area;
When the traffic information from the first FM broadcast station cannot be received by the control means, the second FM broadcast station transmits the traffic information different from the first FM broadcast station via the reception means. Detecting steps,
A traffic information channel selection method characterized by comprising: In the step of acquiring information related to the disaster,
The traffic information tuning method according to claim 6, wherein information related to the disaster is acquired through media other than FM broadcasting. In the step of detecting the second FM broadcast station,
The traffic information tuning method according to claim 6, wherein when a plurality of the second FM broadcast stations are detected, the second FM broadcast station having the strongest received electric field strength is extracted. In the step of detecting the second FM broadcast station,
7. The traffic information tuning method according to claim 6, wherein when a plurality of the second FM broadcast stations are detected, all are displayed via a display means. The first FM broadcasting station is a NHK-FM broadcasting station (NHK is a registered trademark) of each prefecture, and the second FM broadcasting station is a community broadcasting station in a region or a disaster broadcasting station in a municipality. The traffic information channel selection method according to claim 6.

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