JP2006250894A - Onboard navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To preclude a route guide from being disturbed, while restraining a capacity of a picking memory, even when using a map picking function. <P>SOLUTION: This system stores with priority in the picking memory a map data corresponding to a mesh containing a point (guide point) required to be guided with special care such as right and left turn points, out of the map data in a portion along a search route, when using the map picking function. One part of data constituting the map data is thinned as to the mesh not including the guide point to be stored in the picking memory. A data volume stored in the picking memory is restrained thereby, and the route guide is precluded from being disturbed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle navigation device.

  As one function of a conventional in-vehicle navigation device, a part or all of map data originally stored in a large capacity medium such as a DVD (Digital Versatile Disk) or HDD (Hard Disk Drive) is stored in a RAM (Random Access Memory). ) And the like, and there is a function for executing a navigation function using map data on the other medium (hereinafter, this function is referred to as a map cutout function, and this separate medium is referred to as a cutout memory). . By using this map cut-out function, the user can display a map on the screen and continue navigation while guiding to the destination while continuing navigation, such as audio functions such as music and video. Functions other than functions can be executed.

  By the way, generally, since the capacity of the cut-out memory is limited, it is often impossible to store the entire map data. For this reason, usually, a limited part of map data is cut out according to the capacity, and the navigation function is executed using it. Therefore, since the data that can be used is limited as compared with the case where the map data itself is used, the navigation function realized using the map data is necessarily limited. Therefore, in order to realize the map cutout function, in order to limit the navigation function as much as possible, it is necessary to devise how to cut out the map data stored in the cutout memory.

Here, as a technique relating to how to cut out the map data, for example, there is a technique described in Patent Document 1. In the in-vehicle navigation device disclosed in Patent Document 1, map data of a portion along a route set by a user is stored in a cutout memory. Thereby, it is possible to continue guiding at least the vehicle according to the route, and it is possible to suppress the capacity of the cutout memory as compared with the case where all the map data is stored.
Japanese Patent No. 2663003

  However, even if the technique described in Patent Document 1 is used, for example, when the capacity of the clipping memory is not sufficient or when the route set by the user is long, the map data of the portion along the route is stored. In this case, the route guidance to the destination cannot be continuously performed. In this case, it can be considered that the average amount of map data stored in the cutout memory is reduced on all routes. For example, the shape of the road is stored, and the names of roads and intersections are not stored. However, even if this method is adopted, for example, at an intersection where a right or left turn must be made, there is a problem that it often leaves depending on the name of the road or the name of the intersection, so that it leaves the searched route. .

  The present invention has been made in view of the above problems, and even when the map cutout function is used, the vehicle is mounted without reducing the capacity of the cutout memory and causing trouble in route guidance. An object is to provide a navigation device.

  In order to achieve the above object, the in-vehicle navigation device according to claim 1 is more than the first map data storage means for storing map data composed of a plurality of types of data, and the first map data storage means. A second map data storage means for storing a part of the map data stored in the first map data storage means, a setting means for setting a departure place and a destination, and the map; Using the data, the route search means for searching for the route from the starting point to the destination set by the setting means, and the area along the route searched by the route search means are divided into a plurality of blocks. For each of the plurality of blocks, the map data corresponding to each of the plurality of blocks originally has in consideration of the search route belonging to its own block. The object is selected according to the search route using the writing means for selecting data and storing it in the second map data storage means and the map data stored in the second map data storage means. And guiding means for guiding to the ground.

  Thus, in the in-vehicle navigation device according to the first aspect, when the map data of the portion along the search route is stored in the clipping memory, not all of the configuration data is stored, but the predetermined amount is determined as necessary. The data is thinned out and stored. At this time, which data is to be thinned is determined for each block in consideration of the search route. For example, if the searched route belonging to the block does not include an expressway, when the route is guided, the data related to the expressway in the map data is considered to be less frequently used. Therefore, in this case, when the map data corresponding to this block is stored in the cut-out memory, it is considered that there is no problem in route guidance even if data related to the expressway is thinned out.

  Further, when the searched route belonging to the block is a route of only a straight road, it is considered that the vehicle is unlikely to leave the route even if the route is not guided by voice. Therefore, in this case, when the map data corresponding to this block is stored in the cutout memory, it is considered that there is no problem in route guidance even if the guidance voice data in the map data is thinned out.

  Thereby, compared with the case where the map data of the part along a search path | route is memorize | stored in the memory for extraction as it is, the capacity | capacitance of the map data to memorize | store can be restrained low. In other words, when cut-out memories having the same storage capacity are used, map data along a route having a higher data density, such as a map data along a longer route or a city center, can be stored. Further, which data is to be thinned out is determined for each block in consideration of the searched route, so that the route guidance is hardly hindered.

  The in-vehicle navigation device according to claim 2, wherein the writing means includes a guidance point for guiding at least one of a route to be traveled and a predetermined point when performing route guidance during the searched route belonging to the block. In some cases, a plurality of data originally included in the map data is selected so that data to be stored increases as compared with the case where there is no guide point.

  Examples of the “guidance point” include a right / left turn point, a highway entrance / exit (IC), a relay point (JCT), or a point that provides guidance for a destination.

  When route guidance points, it is better to enhance the map data as much as possible to avoid leaving the route. On the other hand, for example, when there are no guidance points in the vicinity, such as a route composed only of a straight road, there is a case where the map data is not so enriched.

  For this reason, the in-vehicle navigation device according to claim 2 has more data to be thinned out when storing map data in the cut-out memory for blocks that do not include guide points than for blocks that include them. is doing. As a result, the amount of data stored in the cut-out memory can be kept low, and route guidance is less likely to be hindered.

  The in-vehicle navigation device according to claim 3, wherein, when the guide point is included in the search route belonging to the block, the writing means originally stores the map data for the block. All the data possessed is written in the second map data storage means.

  As described above, since the map data for the block including the guidance point is not thinned out and is stored in the cutout memory as it is, it is less likely that the route guidance is hindered.

  The in-vehicle navigation device according to claim 4, wherein, when the guide point is not included in the search route belonging to the block, the writing means originally stores the map data for the block. It is characterized in that only predetermined data is selected from the stored data and written into the second map data storage means.

  For example, when guiding a straight route without making a right or left turn, it is unlikely that the user will not leave the route without bothering to give a voice guidance. Further, in this case, since the vehicle only goes straight, it is not necessary to raise the scale of the map displayed on the screen to the city map level. As long as the route is straight, even if other route conditions such as the road type are different, it is not so different. That is, when route guidance is performed for points other than the guidance point, it may be sufficient if the minimum necessary data is available among the data constituting the map data.

  For this reason, in the in-vehicle navigation device according to the fourth aspect, the data to be thinned out is determined in advance for a block that does not include a guide point in the route. As a result, the capacity of the map data stored in the cut-out memory can be kept low, and the route guidance is unlikely to be particularly troublesome. Note that this thinned data may be thinned out as long as the minimum necessary data for continuing route guidance is available.

  The vehicle-mounted navigation device according to claim 5 is configured such that a priority order indicating that the plurality of data originally included in the map data is stored in the second map data storage unit is set, and the writing unit Is set to each data constituting the map data so that the total amount of data to be stored in the second map data storage means does not exceed the upper limit of the storage capacity of the second map data storage means According to the priority order, the data to be written to the second map data storage means is selected for the plurality of blocks.

  If a predetermined data thinning method is employed as in the on-vehicle navigation device of claim 4 described above, for example, when the number of guide points is small on the searched route, the amount of data to be thinned increases. In this case, when map data is stored in the cutout memory, there may be a situation in which an area for storing data still remains in the cutout memory. It goes without saying that even if it is data that is used infrequently in route guidance, it is better to have it than not. On the other hand, for example, if the search route is long or the number of guidance points is large, it may happen that map data cannot be stored in the cut-out memory even if predetermined data is thinned out. .

  For this reason, the vehicle-mounted navigation device according to claim 5 gives priority to each data constituting the map data. When the map data is thinned out and stored, it is stored in the cutout memory in accordance with this priority order so that the total amount of data stored in the cutout memory does not exceed the upper limit of the storage capacity of the cutout memory. The data is determined. Thereby, the capacity of the cut-out memory can be utilized to the maximum, and the above problem can be solved.

  The in-vehicle navigation device according to claim 6 includes priority order setting means for setting, for each block, data to which priority order is selected in consideration of the searched route belonging to the block. Features.

  For example, in the case of route guidance on an expressway, expressway data composed of interchange information, service area information, etc. is necessary among the data constituting the map data. On the other hand, when route guidance is performed on roads other than highways, this highway data is unnecessary. Further, when traveling on a highway, the speed of the vehicle is higher than when traveling on a general road. Therefore, when route guidance is performed on an expressway, there is no problem even if the scale of the map displayed on the screen is not increased compared to when route guidance is performed on a general road. That is, even when route guidance is performed on the same straight road, it is considered that the frequency used for route guidance among the data constituting the map data differs depending on the type of road.

  For this reason, in the in-vehicle navigation device according to the sixth aspect, the priority order is set for each block in consideration of the search route included in each block. Thereby, the map data suitable for the searched route can be stored in the clipping memory.

  Hereinafter, an embodiment of an in-vehicle navigation device according to the present invention will be described.

  FIG. 1 is a block diagram showing the overall configuration of the in-vehicle navigation device 100 according to this embodiment. As shown in the figure, the in-vehicle navigation device 100 includes a position detector 1, a map data input device 6, an operation switch group 7, an external memory 9, a display device 10, a cutout memory 11, a transceiver 12, and a control connected thereto. The circuit 8 is configured. Each component will be described below.

  The control circuit 8 is configured as a normal computer, and includes a well-known CPU, ROM, RAM, I / O, and a bus line for connecting these configurations. In the ROM, a program to be executed by the control circuit 8 is written, and a CPU or the like executes various arithmetic processes according to this program. This program can also be acquired from the outside via the external memory 9. In particular, when the destination is set by the user, the control circuit 8 searches for a recommended route to the destination and performs processing for guiding the vehicle along the searched route. Furthermore, when there is a request to use the map cutout function from the user, the control circuit 8 reduces the data amount of the map data corresponding to the predetermined area out of the map data along the search route, Processing to be stored in the cut-out memory 11 is performed. Details of the processing at this time will be described later.

  The position detector 1 includes a known geomagnetic sensor 2, a gyroscope 3, a distance sensor 4, and a GPS receiver 5 for GPS (Global Positioning System) that detects the position of the vehicle based on radio waves from a satellite. Have. Since these have errors of different properties, they are configured to be used while being complemented by a plurality of sensors. Depending on the accuracy of each sensor, the position detector 1 may be constituted by a part of the above-described parts, and a steering rotation sensor (not shown), a vehicle speed sensor for each rolling wheel, or the like may be used. The current position of the vehicle is detected by the position detector 1, and the control circuit 8 can recognize which position the vehicle is traveling on the searched route when performing route guidance, and the vehicle is in the route. It can be determined whether or not the vehicle is traveling along.

  The map data input device 6 is a device for inputting map data necessary for executing the navigation function. As a storage medium for storing the map data, a writable storage medium such as a memory card or a hard disk can be used in addition to a reproduction-only storage medium such as a CD-ROM or a DVD-ROM.

  The map data further includes various data shown in FIG. “Display map shape data” is data indicating the shape of a road, the shape of a building, and the like to be displayed on the display device 10 described later. Further, as shown in FIG. 2, display map shape data corresponding to each scale is prepared.

  “Guidance map network data” includes link data indicating roads and node data connecting the links. This link divides each road on the map into multiple nodes such as intersections, branches, and merge points, and defines each link as a link. By connecting each link, the road is Composed. Link data is a unique number (link ID) that identifies the link, link length indicating the link length, link start and end node coordinates (latitude / longitude), road name, road type, road width, number of lanes, right turn・ Consists of data such as the presence of the left turn lane, the number of lanes, the speed limit, etc.

  On the other hand, the node data includes a node ID, a node coordinate, a node name, and a link ID of a link connected to the node, each node having a unique number for each node where roads on the map intersect, merge and branch. It consists of data such as ID and intersection type.

  When searching for a route from the starting point to the destination, a passing cost indicating the ease of passing through each link and node is calculated. This passing cost is calculated according to the characteristics of each link (link length, road type, road width, etc.) and the type of straight travel and right / left turn at each node. Then, for an arbitrary route from the departure point to the destination, a route that minimizes the added value of the passing cost of each link and each node constituting each route is searched using a route search method such as the Dijkstra method. Is done.

  The “guidance voice data” is composed of various kinds of voice data output when performing route guidance, such as “Please turn right ahead”.

  “Expressway data” is data specific to an expressway including interchange information, service area information, and the like.

  The “neighboring facility mark data” is composed of marks indicating various facilities. When the above-described “display map shape data” is displayed on the display device 10, these marks are superimposed on the shape indicating the facility. Is displayed.

  The “VICS link data” is transmitted to the display device 10 when the transmitter / receiver 12 described later receives road traffic information (congestion information) from a VICS (Vehicle Information and Communication System) (registered trademark, the following is omitted). It is composed of arrow data indicating the degree of traffic congestion, which is displayed over the road displayed in.

  “Toll data” consists of data indicating the toll of each toll road. When traveling on a toll road, the toll can be grasped in advance by referring to this “toll data”. .

  And the map data comprised from these data is divided | segmented and memorize | stored in the some mesh which covers a predetermined area | region. For example, when displaying a map around the current location, the control circuit 8 reads out the map data of the mesh to which the current location belongs from the map data input device 6 and reads it into the display device 10.

  As the operation switch group 7, for example, a touch switch or a mechanical switch integrated with the display device 10 to be described later is used, and is used for various inputs such as setting of a starting point and a destination when searching for a route.

  The display device 10 is configured by, for example, a liquid crystal display, and the vehicle position mark corresponding to the current position of the vehicle detected by the position detector 1 and the map data input device 6 are input to the screen of the display device 10. Display the surrounding road map. Further, by operating the operation switch group 7, the road map can be changed to a predetermined scale and displayed, or the road map can be scrolled and displayed.

  The cutout memory 11 is a memory that reads out and stores map data along a search route from the map data input device 6 when a user requests to use the map cutout function. At this time, part of the data constituting the map data is thinned and stored as necessary. The cut-out memory 11 may be anything as long as it can store data. For example, a RAM or a flash memory may be used, or a writable removable medium may be used. Further, a part of the external memory 9 may be shared.

  The transmitter / receiver 12 is used for communication connection with the outside. For example, the transmitter / receiver 12 is connected to a VICS sensor that receives road traffic information provided from a VICS center via a beacon laid on a road or FM broadcast stations in various places. Is done.

  The in-vehicle navigation device 100 can execute various functions such as an audio function for operating an audio device (not shown) in addition to a navigation function such as route guidance.

  Next, the flowchart of FIG. 3 shows the process performed by the control circuit 8 when the user requests to use the map cutout function during or after starting route guidance, which is a feature of the present invention. It explains using.

  The present invention has a feature in the storage method when storing the map data of the portion along the searched route in the cut-out memory 11, and therefore it is assumed that the searched route exists. This search route is calculated by the control circuit 8 when the departure point and the destination are set by the user. Specifically, as described above, the control circuit 8 reads “guidance map network data” in the map data from the map data input device 6, and link data constituting the “guidance map network data” and A cost indicating the ease of passing through each node data is calculated. Then, a route that minimizes the total cost attached to the links and nodes constituting the route to the destination is searched using a search algorithm such as the Dijkstra method. At this time, for example, assume that the route shown in FIG. 5 is searched.

  In this way, it is determined whether or not there is a request to use the map cutout function in a state where the route is searched in step S10. For this determination, for example, a switch indicating “map cutout function” is provided. If the user confirms that this switch has been pressed, it is determined that there is a request to use the map cutout function, and if it cannot be confirmed, it is determined that there is no request to use the map cutout function.

  If it is determined that there is no request to use the map cutout function, normal route guidance is executed in step S40.

  On the other hand, if it is determined that there is a request to use the map cutout function, a process of storing the map data of the portion along the searched route in the cutout memory 11 is performed in step S20. Specifically, this is performed according to the flowchart of FIG.

  First, in step S21, referring to the map data stored in the map data input device 6, there is a point (guidance point) that needs to be guided with particular care when performing route guidance on the searched route. Whether or not is determined in units of meshes. Here, the “guidance point” means, for example, a point where guidance is required for a right / left turn point, the vicinity of an expressway entrance / exit (IC), a relay point (JCT), or a destination as a guidance object. (Including guidance target points). In the example of the search route shown in FIG. 5, there are a right turn point 2a, an expressway entrance 2b, an expressway relay point 2c, an expressway exit 2d, and a guidance target point for a destination 2e, each of which is a mesh 1d. 1g, 1j, 1o, 1s. Therefore, there are guide points on the routes belonging to the meshes 1d, 1g, 1j, 1o, and 1s. Conversely, meshes that do not have guide points on the search route belonging to themselves are meshes 1a to 1c, 1e, 1f, 1h, 1i, 1k to 1n, and 1p to 1r.

  Here, when it is determined that there are guidance points on the searched route belonging to the mesh, the map data corresponding to the mesh is read from the map data input unit 6 in the cutout memory 11 in step S23. Remember. At this time, the data constituting the map data (see FIG. 2) is not thinned out, and all data is stored. In the example shown in FIG. 5, the map data corresponding to the meshes 1d, 1g, 1j, 1o, and 1s is stored without being thinned out.

  On the other hand, when it is determined in step S21 that there is no guidance point on the search route belonging to the mesh, in step S22, for these meshes, only predetermined data of the configuration data is obtained from the map data input device 6. Read out and store in the cutout memory 11. That is, predetermined data is thinned out and stored from the data that the map data originally has. Here, which data is to be thinned out of the configuration data of the map data is determined in advance as shown in, for example, FIG. For example, if there is no guidance point, it is considered that the vehicle will rarely leave the searched route without changing the scale of the map displayed on the screen during route guidance to the city map level. The shape data for display at the city map level can be thinned out. Similarly, “display map shape data (1600 m map level)”, “guidance map network data”, “guidance voice data”, “neighboring facility mark data”, and “charge data” can be thinned out.

  Note that the combination of data to be thinned is not limited to this, and any data may be included in the data to be thinned if the vehicle does not leave the route. Further, when the cutout memory 11 having a large storage capacity is used, the number of data to be thinned out may be reduced.

  In the example shown in FIG. 5, the map data corresponding to the meshes 1a to 1c, 1e, 1f, 1h, 1i, 1k to 1n, 1p to 1r is thinned out.

  When the guidance target point is located near the end of the mesh, exceptionally, the map data corresponding to the adjacent mesh may not be thinned out. This is because guidance is easier to understand if guidance is provided to some extent before the guidance target point.

  Then, returning to the flowchart of FIG. 3 again, in step S30, route guidance is performed using the map data stored in the cutout memory 11. At this time, for example, when the map data input device 6 is shared with an audio medium such as a CD drive or a DVD drive, the map data input device 6 can be used as an audio data input device.

  In the route guidance when the map cutout function is used, the navigation function is limited when the vehicle enters the thinned mesh area from the mesh area where the map data is not thinned. At this time, for example, the navigation function may be notified to the user by a speaker (not shown) or the display device 10. Conversely, when a vehicle enters a mesh area that has not been thinned out from the mesh area in which the map data has been thinned out, it is notified that the restriction on the navigation function has been lifted.

  As described above, when using the map cutout function when the search route exists, the vehicle-mounted navigation device 100 according to the present embodiment stores map data corresponding to the mesh of the portion along the search route. At this time, the predetermined data constituting the map data is thinned out and stored in the cutout memory 11 for the mesh having no guide point. On the other hand, the mesh having guide points is stored in the cut-out memory 11 without performing data thinning.

  Thereby, compared with the case where all the map data of the part along a search path | route is memorize | stored in the memory for extraction, the data amount to memorize | store can be restrained low. In other words, when a cut-out memory having the same storage capacity is used, map data of a longer route and a route having a higher data density can be stored as compared with the conventional case. Further, map data in the vicinity of the guidance point is not thinned out, so it is considered that the route guidance will not be hindered.

  Note that when storing map data in the cutout memory 11, which data of the map data corresponding to which mesh is to be thinned is not limited to the above-described example, and does not hinder route guidance. Any method may be used as long as it exists. For example, the methods shown in the following two modifications may be adopted.

(Modification 1)
In this embodiment, when the map data corresponding to the mesh including the guidance points is stored in the cut-out memory 11, all data is stored without performing data thinning. However, even if the guidance points are the same, the data used in the map data is slightly different when the route guidance is performed, for example, between the right / left turn point and the vicinity of the entrance / exit of the expressway. In other words, when guiding the vicinity of the entrance / exit of an expressway, data related to the expressway (“highway data”, “fee data”) is required among the map data, but the right and left turn points are guided. Sometimes these data are not directly related.

  For this reason, when the map data corresponding to the mesh including the guide points is stored in the cutout memory 11, data may be thinned out appropriately in consideration of the attributes of the guide points.

  As a result, the amount of data stored in the cut-out memory 11 can be further reduced. That is, the map cutout function can be used even when the storage capacity of the cutout memory 11 is small or when the map data capacity of the portion along the searched route is large.

(Modification 2)
In the present embodiment, when map data corresponding to a mesh that does not include guide points is stored in the cutout memory 11, data to be thinned out is determined in advance as shown in FIG. Therefore, when this method is adopted, the amount of data stored in the cutout memory 11 changes according to the searched route. That is, for example, when the map data is stored in the cutout memory 11 when the length of the searched route is short, or when the amount of thinning data is large due to the route with few guide points, the map data is still stored in the cutout memory 11. There may be a sufficient capacity for storing data. It goes without saying that even if it is data that is used infrequently in route guidance, it is better to have it than not.

  On the other hand, for example, if the search route is long or the number of guidance points is large, it may happen that map data cannot be stored in the cut-out memory even if predetermined data is thinned out. .

  For this reason, the data to be thinned out may be adjusted according to the search route so that the amount of data stored in the clipping memory 11 is optimized. Specifically, for example, as shown in FIG. 7, a priority is assigned to each data constituting the map data. When the map data is thinned out and stored, it is stored in the cutout memory 11 according to this priority order so that the total amount of data stored in the cutout memory 11 does not exceed the upper limit of the cutout memory 11. Determine the data. Thereby, the capacity of the cut-out memory 11 can be utilized to the maximum extent.

  Note that this priority order is not limited to the example shown in FIG. 7 and may be determined in any way.

  Further, for example, when route guidance is performed on an expressway, expressway data including interchange information, service area information, and the like is necessary among data constituting map data. On the other hand, when route guidance is performed on roads other than highways, this highway data is unnecessary. Further, when traveling on a highway, the speed of the vehicle is higher than when traveling on a general road. Therefore, when route guidance is performed on an expressway, there is no problem even if the scale of the map displayed on the screen is not increased compared to when route guidance is performed on a general road. That is, even when guiding a route where there is no guidance point in the vicinity, it is considered that the usage frequency differs among the data constituting the map data depending on the type of road and the like.

  For this reason, the priority order may be set for each block in consideration of the search path included in each block. Thereby, the map data more suitable for the searched route can be stored in the cutout memory 11.

It is a block diagram which shows the whole structure of the vehicle-mounted navigation apparatus 100 of this embodiment. It is a figure which shows the various data which comprise the map data of this embodiment. It is a flowchart which shows the process which the control circuit 8 of the vehicle-mounted navigation apparatus 100 performs when utilizing a map cutout function. It is a flowchart which shows the process which the control circuit 8 performs the process which thins out the map data of the part along a search path | route as needed, and memorize | stores it in the memory 11 for extraction. It is a figure which shows the mesh (1a-1s) of the part along a search path | route, and the guidance object point (2a-2e) on a search path | route. It is a figure which shows which data is memorize | stored among the data which comprise map data with respect to each with and without a guidance point in a mesh, when storing map data. When there is no guidance point in a mesh, it is a figure which shows which data are preferentially memorize | stored in the memory for extraction among the data which comprise map data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 In-vehicle navigation apparatus 1 Position detector 6 Map data input device 7 Operation switch group 8 Control circuit 9 External memory 10 Display device 11 Cutting-out memory 12 Transceiver

Claims (6)

First map data storage means for storing map data composed of a plurality of types of data;
A second map data storage means for storing a part of the map data stored in the first map data storage means, which has a smaller capacity than the first map data storage means;
A setting means for setting a starting point and a destination,
Using the map data, route search means for searching for a route from the starting point to the destination set by the setting means;
Dividing the area of the portion along the route searched by the route search means into a plurality of blocks, and considering the searched route belonging to its own block for each of the divided blocks, the plurality of blocks Writing means for selecting data originally possessed by the map data corresponding to each of the data and storing the data in the second map data storage means;
An in-vehicle navigation device comprising: guide means for guiding the vehicle to the destination according to the searched route using map data stored in the second map data storage means.   The writing means has no guidance point when there is a guidance point for guiding at least one of a route to be taken and a predetermined point when performing route guidance in the searched route belonging to the block. The vehicle-mounted navigation device according to claim 1, wherein a plurality of pieces of data that the map data originally has are selected so that data to be stored increases as compared with the above.   In the case where the guide point is included in the search route belonging to the block, the writing means stores all the data originally possessed by the map data for the block. The in-vehicle navigation device according to claim 2, wherein the in-vehicle navigation device is written in the map data storage means.   In the case where the guide point is not included in the search route belonging to the block, the writing means stores in advance the data that the map data originally has for the block. The in-vehicle navigation device according to claim 2 or 3, wherein only determined data is selected and written in the second map data storage means. Priorities indicating that the plurality of data originally possessed by the map data are stored in the second map data storage means are set,
The writing means adds to each data constituting the map data such that the total amount of data stored in the second map data storage means does not exceed the upper limit of the storage capacity of the second map data storage means. The in-vehicle navigation device according to claim 2 or 3, wherein data to be written to the second map data storage unit is selected for the plurality of blocks in accordance with a set priority order.   6. The priority order setting unit configured to set, for each block, data to which priority order is selected in consideration of the search path belonging to the block. Car navigation system.

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