JP2011209027A - Route guiding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guide along a non-detouring proper route in the state where a destination is not designated univocally.SOLUTION: Designation of a destination is input in an area such as an administrative district. A navigation device sets a plurality of temporary destinations in the input objective area, and searches for area designation routes to the temporary destinations. The navigation device extracts a common part in the acquired routes, and specifies a branch point where each route is separated. When a present position of a user approaches the branch point, the navigation device urges the user to narrow the destination furthermore, and then narrows an object area within a non-detouring range when the user progresses beyond the branch point. When the destination is specified by narrowing or input by the user, the navigation device is shifted to route search/route guide processing to the specified destination. Hereby, even when the destination is designated roughly, non-detouring route guide can be achieved.

Description

  The present invention relates to a route guidance system that searches and guides a route toward a specified destination.

A navigation system that searches and guides a route from a specified departure point to a destination by using network data representing roads by links and nodes has become widespread.
A user of such a navigation system may not be able to specify the destination position accurately when he / she leaves. This is the case when the destination location is known only vaguely, or when setting the destination, the signal changes and the setting must be interrupted.
In the case where it is not specified accurately as described above, there has been a case where the route search cannot be started conventionally. Further, even when performing a route search, a route search to a point that can be specified within a specified range is performed.

  For example, when a municipality or the like is designated, the location of the designated administrative office is set as the destination. As another aspect, when a municipality or the like is designated, Patent Document 1 obtains each point that is the intersection of the designated administrative world and the road, and among those intersections, the shortest path from the departure point is obtained. A technique for performing route guidance to an intersection is disclosed.

JP 2007-240438 A

However, in the route search of the prior art, an appropriate route for the destination intended by the user is not always obtained.
For example, when the administrative world is wide, the location of the government office may be quite far from the user's true destination. In such a case, a route suitable for the user cannot be obtained by route search using the location of the government office as the destination.
The route search for the intersection of the administrative boundary and the road is the same as in the technique described in Patent Document 1, and the route from the departure point to the intersection on the shortest route is suitable as the route to the user's destination. Not necessarily.
Even if the user resets the destination more accurately on the way, depending on the timing, there is a possibility that the user is already guided to a place where he / she has to turn around unnecessarily compared to the optimal route. It was not always possible to get a good route.

It is possible for a navigation system user to depart in a state where the destination cannot be specified accurately. In such a case, an unsuitable route guidance is provided, which is useful for the navigation system. Will be greatly impaired.
In view of such a problem, an object of the present invention is to make it possible to guide a route that does not cause unnecessary large turns even when a destination is not correctly specified.

The present invention can be configured as a route guidance system that guides a route toward a designated destination.
The route guidance system includes a map database storage unit, an input unit, a temporary destination setting unit, a route search unit, and a route guidance unit.
The map database storage unit stores network data representing roads as nodes and links. Network data can be prepared by mixing a main network that can be used for route search of automobiles in consideration of traffic regulations and a quasi network that can be used for route searches but cannot be completely developed for traffic regulations. Good.

  The input unit inputs a starting point and a destination. As the departure place, the current position of the user may be automatically input. The destination may not be determined unambiguously and may be input with a room for selection. For example, it is possible to take a method of designating in administrative boundaries such as municipalities, a method of designating an arbitrary area on the map, or the like. These designations may be either when the user does not know the location of the destination accurately or when the user departs in the middle of designating the destination by an address or the like. Moreover, the aspect which designates the destination of several points may be sufficient.

The temporary destination setting unit sets a plurality of temporary destinations used for route search within the range of the designated destination. Various settings are possible for the temporary destination. When destinations are designated at a plurality of points, all or part of the designated destinations may be treated as temporary destinations. When a destination is designated in an area such as an administrative boundary, an arbitrary point existing in the area or on the boundary can be selected and set as a temporary destination. The number of temporary destinations can be set arbitrarily.
When the destination is designated by an area, it is preferable that the centroid of the area and the set deviation of the center of gravity position of all the temporary destinations coincide with each other or be set within a sufficiently narrow predetermined range.

The route search unit searches the route from the departure point to each temporary destination with reference to the network data. And a route guidance part performs route guidance to the point where the route to each temporary destination branches. When a route from the departure point to a plurality of temporary destinations is searched, the route is common to all the temporary destinations until the middle, and the route is divided according to the temporary destinations from the middle. The route guidance unit performs route guidance to a branch point where the route is divided.
In this way, according to the route guidance system of the present invention, the route guidance is performed in the range common to the temporary destination set within the destination range, so the route to be guided is within the designated range. It is an appropriate route to any point. If the user designates the destination in more detail and accurately while the route guidance to the branch point is being made, the user can obtain an appropriate route that does not require unnecessary round trips to the destination.

In the present invention, when the departure point is close to the designated destination range, there is a case where a common part does not occur in the route to the temporary destination. In such a case, the route guidance system may issue an instruction to narrow the destination range. The route guidance may be started when a common part occurs in the route to the temporary destination.
In addition, when the user's current position approaches the branch point during route guidance, the route guidance system notifies the user that the branch point is approaching, or provides more detailed information about the destination. It is preferable to instruct to set the value.
By taking these aspects, it is possible to realize route guidance that avoids unnecessary large turns.

In the present invention, a route search using the arrival point may be performed as shown below.
First, the map database stores feature data for drawing features including roads in addition to network data. And the arrival point acquisition part which acquires an arrival point with reference to network data and feature data is provided. The arrival point is a point on the road where the network data is maintained as a road through which automobiles can pass, and can be reached directly from a feature corresponding to the destination or through any road.
The arrival point may be set for each feature such as a building as a part of the feature data. In this case, the arrival point acquisition unit need only read the arrival point data corresponding to the feature designated as the destination. When the destination is designated by the coordinate value, the arrival point acquisition unit may identify the feature corresponding to the designated coordinate and read the data of the arrival point corresponding to the feature.
On the other hand, it can also be set as the structure which does not prepare an arrival point beforehand. In this case, the arrival point acquisition unit finds the arrival point by route search starting from the destination. For route search in this case, it is possible to use a quasi-network where traffic regulations are not completely developed, and roads where no network is established. For roads that do not have a network, it is possible to search for a route by treating the degree of connection of polygon data of roads included in the feature data as network data. In order to find an appropriate arrival point by route search, it is preferable to store the line segment from the entrance / exit of each feature to the nearest road as the entrance / exit line in the feature polygon data.

  Thus, in route guidance using arrival points, route guidance can be performed in consideration of entrances and exits of features such as buildings. In a system capable of such route guidance, the usefulness is increased only when the destination feature is accurately specified. However, at the time of departure, there are cases where the destination cannot be specified accurately. Even when the destination is not completely specified, the present invention in which an appropriate route is guided can further improve the convenience of the system capable of guiding the route in consideration of the entrance / exit of the feature. Therefore, it can be said that the necessity and usefulness are high.

In the present invention, the route guidance unit displays a map in a display mode that can identify the correspondence between each route and the destination that can be reached by the route for the portion after the route to each temporary destination is branched. May be. For example, when the route is divided into left and right after the branch point, the destination that can be reached through the right route and the destination that can be reached through the left route are displayed in an identifiable manner.
As an identifiable display mode, for example, a mode in which the destination is displayed in different colors for each route is exemplified. In this case, it is more preferable to display the destination and the route toward the destination in the same color. As another display mode, a message or a list indicating a reachable destination may be displayed in association with the route.
By displaying the route and destination in correspondence with each other in this way, the user can determine which route to proceed even if the correct destination cannot be specified even when the branch point is reached. It becomes.
In order to realize the guidance in this aspect, it is necessary to search for a route from the branch to each destination. This route search can be performed at various timings. It may be performed before the route guidance is started, or may be performed in parallel with the route guidance during the period from the start of the route guidance to the arrival at the branch point. According to the latter aspect, there is an advantage that route guidance can be started promptly without waiting for the route search to each destination to end.

In the present invention, when route guidance is performed according to the current position, various methods can be taken when a user passes through a branch point of a route to a temporary destination.
For example, the route search unit may perform route search again for each temporary destination. Since it has passed the branch point, depending on the temporary destination, a newly obtained route may require a route change from the route before the branch point has elapsed. The route search unit can extract a temporary destination that can be reached without changing the route compared to the previous route by comparing the newly obtained route with the previous route. Of the temporary destinations that require a route change, in particular, only the temporary destination where the route after the route change is larger than the previous route, that is, the route becomes longer, may be extracted. It is also possible to extract a temporary destination that is assumed to be a large turn based on the distance, direction, and the like from the current position to each temporary destination without performing route search again.
Therefore, the route guidance system displays the temporary destination extracted in this manner in a display mode that can be distinguished from other temporary destinations. For example, it is possible to change the color of the extracted temporary destination, increase the brightness, or display a mark that can be easily identified. By doing so, the user can know the range of destinations that can be reached without changing the route from the current position, and the range of destinations that can be reached without making a large turn even if the route needs to be changed.
If the user comes to the vicinity of the destination, the user can generally know in which direction the destination is, and the user may select a route by his / her own judgment without specifying the destination again. According to the above-described aspect, in such a case, the user determines whether or not the route selected by the user is correct by confirming that the intended destination is a conspicuous display aspect. It becomes possible.

  In the route guidance system of the present invention, even if the destination is initially input in a manner in which the destination is not uniquely determined, in the course of the route guidance, the range of the destination is narrowed down and specified, A specific destination may be specified completely. By doing so, it is possible to present an appropriate route sequentially to the newly designated destination. In addition, if the destination is newly narrowed down before branching, there is no need to go around unnecessarily from the previous route.

In this way, when the destinations can be narrowed down sequentially, if the current position of the user has passed the branch point, the route guidance system performs the route search again as described above, and the previous route Thus, it is possible to identify a temporary destination that requires a route change and a temporary destination that does not.
When the route search is performed again in this way, the route guidance system further increases the temporary destination where the route change exceeds the allowable range, for example, the difference between the route after the change and the previous route exceeds the allowable range. For temporary destinations where the number of turn left and right after the route change exceeds the allowable range, temporary destinations that need to make a U-turn and go in the opposite direction of travel, etc. You may display a map in the aspect excluded from the object of the destination which can be designated. For example, a temporary destination whose route change exceeds an allowable range may be displayed in an inconspicuous color such as so-called gray out, the display of the temporary destination itself may be deleted, or the luminance may be reduced. By doing so, the user can specify the destination within a range in which the route change does not exceed the allowable range.
When a user passes through a branch point, as described above, an approximate registration of the destination is often obtained. In other words, when the user makes a new input for narrowing down the destination at this time, it is normal to specify the range within which the route change does not exceed the allowable range, such as a range that does not become a large turn. From the above viewpoint, since the map is displayed in a manner that excludes the temporary destination that requires a route change that exceeds the allowable range, the above-described aspect avoids unnecessary temporary destinations from entering the user's field of view. It is possible to provide a screen that can easily narrow down the destination.

Even if the user does not correctly specify the destination, the user may intend to specify a destination that has been visited before.
In order to cope with such a case, the route guidance system may be provided with a history storage unit that records the history of the previous route search result. It is only necessary for the history to record at least the destination visited by the route search.
Then, when the user designates the destination, the route guidance system refers to the history storage unit and adds the destination in the previous route search result within the predetermined range from the designated destination. A temporary destination may be set. The destination obtained from the history may be used as a temporary destination as it is, or a range including the obtained destination and the destination specified by the user is set, and the temporary destination is set in this range. May be.
By doing so, route guidance based on the previous history can be performed. Therefore, even if the user has made an incorrect specification with the intention of specifying a destination that the user has visited before, an appropriate route can be presented for the visited destination.

  In addition, the present invention may be configured as a route guidance method using a computer, or may be configured as a computer program for causing a computer to execute such route guidance. Moreover, you may comprise as a computer-readable recording medium which recorded such a computer program. Recording media include flexible disks, CD-ROMs, magneto-optical disks, IC cards, ROM cartridges, punch cards, printed matter printed with codes such as bar codes, computer internal storage devices (memory such as RAM and ROM), and Various media that can be read by a computer, such as an external storage device, can be used.

It is explanatory drawing which shows the structure of a route guidance system. It is explanatory drawing which shows the structure of a map database. It is explanatory drawing shown about the setting of an arrival point. It is a flowchart of a route guidance process. It is a flowchart of a screen input process. It is explanatory drawing which shows the example (1) of setting of a reference | standard target area. It is explanatory drawing which shows the example (2) of a setting of a reference | standard target area. It is explanatory drawing which shows the example (3) of setting of a reference | standard target area. It is explanatory drawing which shows the example (1) of setting of a character purpose area. It is explanatory drawing which shows the example (2) of setting of a character purpose area. It is explanatory drawing which shows the example of a setting of a log | history destination. It is explanatory drawing which shows the example which sets a building group as a destination area. It is a flowchart of an area designation route search process. It is a flowchart of an area route guidance process. It is explanatory drawing which shows an area route guidance example (1). It is explanatory drawing which shows an area route guidance example (2). It is explanatory drawing which shows an area route guidance example (3). It is explanatory drawing which shows a route guidance example.

Embodiments of the present invention will be described in the following order.
A. System configuration:
B. data structure:
B1. Network data:
B2. Character data:
B3. Feature data:
B4. Setting the arrival point:
C. Route guidance process:
C1. Screen input processing:
C2. Area specified route search processing:
C3. Area-specific route guidance processing:
D. Route guidance example:

A. System configuration:
FIG. 1 is an explanatory diagram showing the configuration of the route guidance system. The route guidance system is configured as a navigation device 100. In this embodiment, the navigation apparatus 100 is connected to the server 200 that provides map data and the like through the network NE, and can receive the update of the map database from the server 200. The navigation device 100 may be configured to operate stand-alone, or may be configured to execute part of its functions on the server 200 or the like.

  The server 200 includes a map database storage unit 210, a transmission / reception unit 201, and a database management unit 202. Although the transmission / reception unit 201 and the database management unit 202 may be configured in hardware, in this embodiment, the transmission / reception unit 201 and the database management unit 202 are configured in software by installing a computer program that realizes these functions.

The transmission / reception unit 201 communicates with the navigation device 100 via the network NE. In the present embodiment, data stored in the map database storage unit 210, a command for requesting provision thereof, and the like are communicated.
The database management unit 202 reads the map information requested from the navigation device 100 from the map database storage unit 210. The map database storage unit 210 stores feature data 211, character data 212, and network data 213.
The feature data 211 is polygon data of features to be drawn on a map such as roads and buildings. The character data 212 is character information to be displayed on the map. For example, text information such as a building name and a place name is included. The network data 213 is data representing roads as nodes and links.

The navigation device 100 includes various functional blocks that operate under the main control unit 101. In the present embodiment, the main control unit 101 and each functional block are configured by installing software that realizes the respective functions, but part or all of them may be configured by hardware.
The transmission / reception unit 102 communicates with the server 200 via the network NE. In this embodiment, transmission / reception of a map database and a command for receiving the map database are mainly performed.
The command input unit 103 inputs an instruction from the user through operations of buttons, levers, touch panels, and the like provided in the navigation device 100. Examples of instructions in the present embodiment include designation of a starting point and a destination for route search.
A GPS input unit 104 serving as a current position input unit inputs a user's current position using GPS (Global Positioning System).
The map database storage unit 105 stores the map database provided from the server 200. In the present embodiment, the entire map database stored in the map database storage unit 210 included in the server 200 is also stored in the map database storage unit 105 in the navigation device 100, but is necessary for route search and map display. It is good also as what acquires only the part which becomes from the server 200 each time. The map database storage unit 105 also records previous route search and route guidance history. The history records the date and time when the route search / guidance was performed, the departure point specified by the user, the information on the destination, the information on the destination actually guided, and the like.
The route search unit 107 performs a route search with reference to the map database storage unit 105.
The display control unit 106 displays the map and the searched route on the display of the navigation device 100 using the map database storage unit 105.

B. data structure:
FIG. 2 is an explanatory diagram showing the structure of the map database. An overview of information stored in feature data, character data, and network data is shown.

B1. Network data:
Network data is data representing roads as links and nodes. In this embodiment, two types of network data, main network data and semi-network data, are prepared. In the figure, links L1 to L4 and nodes N1 and N2 indicated by solid lines are main network data, and links L11 to L13 and nodes N11 and N12 indicated by broken lines are semi-network data.
Both main network data and semi-network data store link data and node data belonging to each. The link data records the coordinates of the point sequence forming each link, the type of national road / prefectural road, the number of lanes, other attribute information, and traffic regulation information. The node data records coordinate values, traffic restrictions, and the like.
However, the main network data is data whose traffic regulations have been sufficiently established by field surveys, and can be used without any trouble for vehicle route search. On the other hand, the quasi-network data is data that cannot be said to have sufficient traffic regulations, and is preferably not used in the vehicle route search. Also in this embodiment, the route search is basically performed using the main network data.

B2. Character data:
The character data 212 is data defining a character for displaying a feature name or a place name. In the figure, an example of data for displaying the name of the building BLD is shown. Character data stores information such as contents, position, feature, font, size, and the like.
The content is a character string to be displayed, and in the example in the figure, is the company name “ΔΔ (stock)”.
The position is a position where a character is displayed. In this embodiment, the coordinate value is designated with the lower left point P5 of the character string as a reference point.
The feature is a polygon name of the feature data with which the character is associated.
The font and size are designation of the font and size for display.
In addition, various attributes such as color and bold may be specified.

B3. Feature data:
The structure of the feature data 211 is shown by taking the building H1 as an example. The feature data 211 is polygon data for drawing features such as buildings and roads, and stores names, shapes, representative points, doorway lines, arrival points, attributes, and the like.
The name is the name of the feature. An ID unique to the polygon may be used.
The shape is a sequence of coordinates indicating the vertexes of the polygon of the feature. In the illustrated example, the coordinates of the vertices P1, P2, P3, and P4 of the polygon of the building H1 are stored.
The representative point is the coordinates of the point C that represents the position of the feature. The representative point often uses the centroid of the feature, but can be set arbitrarily.
The entrance / exit line is information for associating a feature with a road. In the case of the building H1, a line segment D for exiting from the entrance to the road is registered as an entrance / exit line. Specifically, the coordinates of both ends of the line segment D are registered. As for the entrance / exit line, only the end point on the road among the line segment D may be registered. In addition, the entrance / exit line is set for a feature such as a building or a parking lot, and it is not necessary to set it for all the features. In the example in the figure, the entrance / exit line DB1 on the front side for the building BLD, the entrance / exit line DB2 on the parking lot BLDP side, the entrance / exit lines DH2 to DH4 for the buildings H2 to H4, and the entrance / exit line DPK for the parking lot PK are set. Has been.

The arrival point G is a point on the network that can be reached from an end point on the road of the feature entry / exit line via any road. In the case of the building H1, the arrival point G is set on the link L2 because it can reach the link L2 via the road R21 associated with the entrance / exit line D as indicated by the dotted line in the drawing. It is also possible to follow the road R21 from the entrance / exit line D in the right direction in the figure, turn right at the node N11 and take a route to the node N2, and use the node N2 as an arrival point. In the present embodiment, since the route from the building H1 to the node N2 is shorter than the route from the building H1 to the node N2, the setting is made in this way. Since the arrival point need not be limited to one, the node N2 may also be set as the arrival point.
In the example of the figure, the arrival point for the buildings H2 to H4 is set as a point GH. For the building BLD, the points GH and GBLD2 are set. The arrival point can be set in the parking lot as well as the entrance / exit line, and in the example shown in the figure, the arrival point GPK is set for the parking lot PK. Since the parking lot PK faces the link L2, the end point of the entrance / exit line DPK and the arrival point GPK coincide with each other.

B4. Setting the arrival point:
FIG. 3 is an explanatory diagram showing setting of arrival points. The arrival point for the entrance / exit line DB of the building BLD1 is shown.
As main network data around the building BLD1, there are a link L7, a node N7, links L5 and L6, and nodes N5 and N6. As the quasi-network data, there is a link L14 indicated by a broken line.
The route reaching the main network from the entrance / exit line DB of the building BLD1 via one of the roads includes three types shown by dotted lines in the figure. The route reaches the link L7 via the road R24, and the route reaches the link L6 and the link L5 via the road R25. The points where these routes reach links L7, L6, and L5 are arrival points G7, G6, and G5.

These arrival points can be obtained by route search. In this embodiment, each feature is associated with one of the roads by an entry / exit line, so the arrival point may be obtained by route search starting from the entry / exit point, that is, the end point on the road of the entry / exit line. .
This route search may use all of the main network data, quasi-network data, and road polygons. Road polygons are not composed of links and nodes, but because there is data specifying adjacent polygons, the relationship between polygons is defined, and as with links and nodes, routes It can be used for searching. As a result of the route search starting from the entrance / exit point, a point where the main network data is reached may be set as the arrival point.

When three arrival points G7, G6, and G5 are found as in the example of the figure, these three points may be used as the arrival point of the building BLD1, for example, the point where the road from the feature is the shortest , Even if you select by the criteria such as the point with the shortest distance from the feature, the point where there is a lot of overlap between the route from the feature to the arrival point and the quasi-network data, or the point close to the direction from the feature to the departure point Good.
In the example shown in the figure, if the route or distance from the feature is selected as a reference, the point G5 closest to the building BLD1 is the arrival point. If an overlapping portion with the quasi-network data is selected as a reference, the point G6 becomes the arrival point. If the departure point is in the leftmost direction in the figure, the point G7 becomes the arrival point if the direction of the departure point is selected as a reference.

  In this embodiment, the arrival point is set according to the above-described procedure, and is set in advance in the feature data 211. The arrival point may not be set in advance, but may be obtained in the course of processing such as route search.

C. Route guidance process:
FIG. 4 is a flowchart of route guidance processing. This is a process mainly executed by the route search unit 107 and the display control unit 106 of the navigation device 100, and is a process executed by a CPU (hereinafter simply referred to as “CPU”) of the navigation device 100 in terms of hardware.
In the following, first, the overall flow of the route guidance process will be described, and then the process performed in the process will be described in detail.

First, the CPU inputs a departure place (step S100). The departure point may be specified by the user, or the current position acquired by GPS or the like may be set as the departure point.
The destination is processed differently depending on the input mode (step S102). In the present embodiment, an input mode using a keyboard or the like and an input mode using a map screen displayed on the navigation device 100 can be selected. The keyboard may be provided in the navigation device as hardware, or may be a software keyboard displayed on the screen.
When the input mode using the keyboard is designated (step S102), the CPU inputs the designated information through the operation by the user (step S104).
If the input mode using the map screen is designated, screen input processing is executed (step S110). The screen input process is a process of inputting a destination by designating a destination point or a predetermined area including the destination on the map screen. The details of the process will be described later.

Next, the CPU determines whether the destination is uniquely specified by the user-specified content (step S130). When the destination is specified as one point or a single feature, a route search for the destination is performed (step S180). This process is a well-known route search process when the departure point and the destination are specified.
Then, route guidance for the searched route is performed (step S182). In this embodiment, route guidance in a state where the destination is uniquely specified is referred to as “destination route guidance”. The destination route guidance displays the route and the current position while detecting the current position of the user, and is executed until the user arrives at the destination (step S184). Voice guidance may also be provided for route guidance.

On the other hand, when the destination is not uniquely identified (hereinafter, this designation is referred to as “area designation”) (step S130), an area designation route search is performed (step S140). This means that if multiple destinations are specified, or if a destination is specified in an administrative area or the like, an excessive round will not occur for any of the specified destinations. This is a process for searching for a route. Details of the processing will be described later.
Then, the CPU guides the route with respect to the route thus obtained (step S150). In the present embodiment, guidance in a state where the destination is not uniquely determined is referred to as area route guidance with respect to the destination route guidance (step S182) (step S150). Although details of the process will be described later, the navigation device 100 narrows down destinations according to the current position of the user even during area route guidance. Even if the user does not specify the destination again, the destination can be reached without making a large turn while traveling along the route, that is, without changing the route so that the route becomes larger than the previous route. May be squeezed by itself. As a result, depending on the route, a single destination may be specified.
When the destination is specified as one (step S170), the navigation device proceeds to destination route search (step S180) and route guidance (steps S182 to S184).

During the area route guidance (step S150), if the destination cannot be specified by the route traveled by the user and the user does not perform an input operation of the destination (step S175), the navigation device 100 displays the area route. The guidance (step S150) is repeated.
On the other hand, even during area route guidance, the user may specify a destination again. In some cases, the destination previously specified by the range or the like may be further narrowed down, or the destination may be changed to a completely different destination. In any case, when such a destination input operation is performed (step S175), the navigation device 100 executes processing after the destination input processing (step S102 and subsequent steps). If the destination is uniquely specified (step S130), destination route search (step S180) and route guidance (steps S182 to S184) are executed, and if the destination is not specified ( Step S130), area route search (step S140), and area route guidance (step S150) are executed again.

The navigation device 100 performs route guidance until the user arrives at the destination by the above processing.
As described above, the present embodiment is characterized in that the area route search process (step S140) and the area route guidance process (step S150) are performed in a state where no single destination is specified. Even when the route guidance process is executed, the process shifts to the destination route search (step S180) and the destination route guidance (step S182) according to the user's subsequent progress and the designation of the destination.
Hereinafter, the contents of the screen input process (step S110), the area designated route search process (step S150), and the area route guidance process (step S160) will be described in detail.

C1. Screen input processing:
FIG. 5 is a flowchart of the screen input process. This is a process of inputting designation of a destination using the map screen displayed on the navigation device 100, and is a process mainly executed by the command input unit 103.
The navigation device 100 inputs the coordinate point designated by the pointer (step S111). In some cases, only one point is specified, and in other cases, a plurality of points are input so as to form a closed region on the map screen.
The accuracy of the specified point varies depending on the displayed map hierarchy. When a wide-area map is displayed (hereinafter sometimes referred to as “higher hierarchy”), the accuracy of the designated point is lowered. On the other hand, when a detailed map is displayed for a narrow area (hereinafter sometimes referred to as “low hierarchy”), the accuracy of the designated point is high. In the present embodiment, in consideration of such a difference in accuracy, the process of replacing the designated coordinate point with the destination area designation is varied according to the hierarchy. Which range of hierarchies is called the lower hierarchy can be arbitrarily determined according to the number of hierarchies that can be displayed by the navigation apparatus 100, the level of detail of each hierarchy, and the like.

In the case of a higher hierarchy (step S112), the navigation device 100 first sets a reference destination area including a designated point (step S113).
FIG. 6 is an explanatory diagram showing a setting example (1) of the reference target area. As shown in FIG. 6A, a case is considered where a point (arrow A6) in the northeastern Kyushu area is designated in a state where a wide-area map that includes about half of Kyushu is displayed on the navigation device 100. FIG. 6B is an enlarged view of the designated coordinate point P6. When the designation is made in such a wide area, it cannot be said that the designation accuracy is high. Therefore, the navigation device 100 defines an area having a predetermined radius r6 centered on the actually designated point P6 as the reference target area AR6. Set. The radius r6 may be a fixed value set in advance, or may be changed according to the hierarchy in FIG. In this example, the reference target area AR6 is circular, but the shape can be arbitrarily set such as a rectangle.

FIG. 7 is an explanatory diagram showing a setting example (2) of the reference target area. Consider a case where a point P7 shown in FIG. In this example, the reference target area A7a is set based on the administrative boundary including the point P7. In FIG. 7A, the reference target area A7a is set at the boundary of the ward, but may be set at the boundary of the city, the boundary of the prefecture, and the like. Which administrative boundary is used as a reference may be changed according to the hierarchy of the map.
FIG. 7B shows an example in which the user designates a plurality of points and designates the destination in the closed area. In this case, a closed region that smoothly connects the designated points is set as a reference target area A7b. A region having a specified shape such as a circle or a rectangle that includes a specified point may be used as the reference target area. This designation is useful when the user grasps the location of the destination to the extent of “approximately here”. Compared to FIG. 7 (a), it is possible to narrow down the reference destination area rather than setting boundaries in administrative boundaries, and it is also possible to specify an area that spans multiple administrative boundaries. There is.

FIG. 8 is an explanatory diagram showing a setting example (3) of the reference target area. Consider a case where a point P8a shown in FIG. In this example, the rectangular area Ar8 including the point P8a is set, the rectangular area Ar8 is divided by the river R8, and the area including the point P8a is set as the reference target area Ar8a. A circular area or the like may be used instead of the rectangular area Ar8. The example of FIG. 8A is an example that reflects the user's intention that the destination exists on at least one of the rivers (the left side in the figure) when the river R8 exists. Other than rivers, lakes, tracks, etc. may be used as boundaries of the standard destination area. The process with the river as a boundary is preferably applied when the river is displayed on the map to such an extent that it can be clearly identified. Therefore, the process may be applied only when the river is displayed at a low level.
Similarly, FIG. 8B is a processing example with a river as a boundary. In this example, the rectangular area Ar8 including the point P8b is divided into meshes as indicated by broken lines, and the reference target area is set by combining the meshes. For the river R8, the mesh on the opposite bank side of the point P8b and the mesh in which the river and the other bank occupy more than half are excluded from the rectangular area Ar8. As a result, a region indicated by a solid line in the drawing is set as the reference target area Ar8b.

Returning to FIG. 5, the screen input process will be described.
In the setting of the reference destination area (step S113 in FIG. 5), it is not necessary to perform the setting according to all the modes described in FIGS. 6 to 8, and any setting may be performed. Which of the modes described with reference to FIGS. 6 to 8 may be determined in advance, or may be selectable by the user at the time of input. You may use the aspect of FIGS. 6-8 properly according to the hierarchy of a map.

  The user may click on a portion where characters on the map are displayed. In such a case, the user may intend to designate a point corresponding to the character as the destination. Therefore, when the designated point designated by the user is included in the area surrounding the character on the map, the navigation device 100 sets the character target area based on the character in this area (step S114). .

FIG. 9 is an explanatory diagram showing a setting example (1) of the character target area. Consider a case where the user clicks on the characters “Tokyo Station” on the map screen shown in FIG. In this embodiment, the character area C9 is set so as to include the character string “Tokyo Station”, and when the point designated by the user (the point P9 ahead of the arrow A9) exists in the character area C9, It is determined that the character string “station” is clicked.
FIG. 9B shows an enlarged state around the character area C9 of “Tokyo Station”. Point P9 is a coordinate point actually designated by the user. As described above, when the user designates the character area C9, the intention is that the destination is “Tokyo Station” corresponding to the character, or the intention is to use the coordinate point actually designated as the destination. I can't determine if it was happening. Therefore, in this embodiment, both are treated as destinations. That is, the predetermined area AR91 centered on the coordinate point P9 actually specified and the predetermined area AR92 centered on Tokyo Station are set as the target area. Of these, the area AR91 centered on the designated coordinate point has already been set in the reference target area described above (step S113 in FIG. 5), so the character target area is centered on Tokyo Station. An area AR92 is set.
The size of the character purpose area AR92 can be arbitrarily set. Since the character is designated, it is determined that the user's intention is relatively clear, and the area may be narrower than the reference target area AR91. Further, only the point or area corresponding to the character designated by the user may be set as the character purpose area. In this case, in the case of “Tokyo Station”, only that point is set as the character purpose area. If a character that designates an administrative boundary is clicked such as “Sumida-ku”, the administrative boundary is set as the character purpose area.

FIG. 10 is an explanatory diagram of a character target area setting example (2). As shown in FIG. 10A, a case is considered in which the user designates a point P10 beyond the arrow A10 on the map in which the area RAa of the A complex and the area RAb of the B complex are displayed. A plurality of buildings exist in each of the A complex and the B complex, but in this hierarchy, the individual buildings are not displayed but are only shown as regions. The designated point P10 is included in the character area “A housing complex”.
FIG. 10B shows the setting state of the target area. Also in this example, a reference target area AR101 centered on the actually designated coordinate point P10 and a character target area AR102 based on the characters “A housing complex” are set. The character purpose area AR102 may be set as a rectangular area (broken line in the figure) including the A complex RAa, or may be a region RAa (hatched area in the figure) of the A complex.

  Returning to FIG. 5, the screen input process will be described. When the character destination area is set, the navigation device 100 refers to the destination history (step S115), and extracts the history destination close to the designated point from the destinations in the history (step S116). In the present embodiment, the destination history is recorded in the map database storage unit 105 of the navigation device 100, and the history includes the date and time when the route search / guidance is performed, the departure location specified by the user, destination information, Information on destinations that are actually guided is recorded.

FIG. 11 is an explanatory diagram showing an example of setting a history destination. As shown in FIG. 11A, consider a case where the user designates a point P11 on the map screen. A rectangular reference destination area AR11a is set around the designated point P11.
The navigation device 100 refers to the history and searches for a destination that has been visited in the past within a predetermined distance r11 from the designated point P11. As a result, the building DES11 is searched. As shown in FIG. 11B, the navigation device 100 expands the reference destination area AR11a to include the building DES11 and sets a new destination area AR11b. Aside from the reference destination area AR11a, a mode in which the building DES11 is added as a destination may be taken, or a region separate from the reference destination area AR11a may be provided around the building DES11.
Although FIG. 11 shows an example of searching for a destination that has been visited in the past only by a distance from the designated point P11, various methods can be used for searching for a destination based on history. For example, the starting point and the destination may be considered comprehensively. That is, it is possible to search for a destination whose destination is close to the designated point P11 from among those whose starting point recorded in the history matches or is close to the current starting point. Further, a destination designation history by the user may be taken into consideration. That is, the designation of the destination by the user may be recorded as a history, and the designated destination may be searched for near the designated point P11. When heading to a specific destination, there is a tendency depending on the user in how to specify the destination, so refer to the destination specification history and specify the destination based on the user's tendency. Is possible.

  The navigation device 100 combines the reference destination area, character destination area, and history destination described above as a destination area (step S117). An area including these three types of target areas may be set, and this area may be designated as the target area.

Next, returning to FIG. 5, processing when a map is displayed in a lower hierarchy will be described. When a map is displayed at a low level, that is, when a detailed map is displayed in a narrow range (step S112), a building group close to the designated point is designated as the target area (step S118).
FIG. 12 is an explanatory diagram illustrating an example of setting a building group as a target area. The housing estates RAa and RAb are displayed on the map. The housing complex RAa has buildings Ha1 to Ha3, and the housing complex RAb has buildings Hb1 to Hb5. Consider a case where the point P12 is designated in this state.
The navigation device 100 sets a circular area (broken line in the figure) having a predetermined radius r12 centered on the point P12 as the reference target area. However, in a state where the map is displayed in such a state that individual buildings can be discriminated as described above, it is normal that the user intends to designate a building in the housing complex RAb, not a building in the housing complex RAa. Therefore, the navigation device 100 designates a building group including the buildings Hb4 and Hb5 belonging to the housing complex RAb including the point P12 among the buildings included within the range of the radius r12 from the point P12. The building Ha3 in the housing complex RAa exists in the area of the radius r12, but is not included in the destination area.
Here, in this embodiment, the term “destination area” means a state in which the destination is not uniquely determined. Therefore, a state in which two buildings are designated like buildings Hb4 and Hb5 is also “ It shall be referred to as a “target area”.
Also in the example of FIG. 12, the target area can be set in various ways. For example, an overlapping area between the housing complex RAb and the radius r12 may be set as the target area.

The navigation device 100 executes processes such as area designation route search (step S140 in FIG. 4) and area route guidance (step S150) shown in FIG. 4 based on the target area designated by the processing described above.
In the above-described screen input process (FIG. 5), an example of processing in which a destination area is designated as a result in both the high hierarchy and the low hierarchy, that is, a process example in which the destination is not uniquely specified in any hierarchy is shown. . A mode in which a coordinate point specified by the user is directly input as a specific destination may be provided by switching the input mode or the like or according to the hierarchy. In this case, the navigation device 100 executes destination route search (step S180 in FIG. 4), destination route guidance (step S182), and the like.

C2. Area specified route search processing:
FIG. 13 is a flowchart of area designation route search processing. In step S140 of the route guidance process (FIG. 4), the route search is performed in a state where the target area is designated.

First, the navigation device 100 inputs a designated destination area (step S141).
Then, a plurality of temporary destinations are selected within the destination area (step S142). The temporary destination is a point that is a destination for a route search described later.
An example of setting a temporary destination is shown in the figure.
The left side is an example when a circular destination area AR13 [0] is set. Temporary destinations were set at the center point D13 [0] of the destination area AR13 [0] and the boundary bisectors D13 [1] to D13 [8]. This is an example in which the centroid positions of the temporary destinations D13 [0] to D13 [8] coincide with the centroid of the destination area AR13 [0]. In this way, temporary destinations can be set evenly within the destination area. The number of temporary destinations on the boundary is not limited to 8 and can be set arbitrarily, but at least 4 points or more should be provided in order to avoid bias in both the vertical and horizontal directions in the figure. preferable.
On the right side of the figure is an example where a rectangular target area AR13 [1] is set. An example is shown in which temporary destinations D13 [10] to D13 [13] are randomly set from the destination area AR13 [1]. The number of temporary destinations can be set arbitrarily.
When the destination area is circular, the temporary destination may be set randomly, or when the destination area is rectangular, it may be set equally on the boundary and inside.

The temporary destination can be set by various other methods. For example, the destination area may be divided into meshes as shown in FIG. 8, and a temporary destination may be set at random for each mesh. By doing so, even when setting at random, it is possible to reduce the bias of the temporary destination.
A destination that has been visited can be set as a temporary destination by referring to the past history.
A predetermined number of temporary destinations may be set for each administrative boundary.
As will be described later, since the route search is performed for each set temporary destination, in order to reduce the load of the route search processing, in any of the modes described here, the set temporary destination It is preferable to provide an upper limit for the total number.
In addition, in order to obtain an appropriate route that does not make a detour at any point in the destination area, it is preferable that the temporary destination is distributed evenly throughout the destination area. It is preferable to set the temporary destination so that the deviation from the centroid of the destination area is within a predetermined value.

When the temporary destination is set, the navigation device 100
A route search to the arrival point of each temporary destination is performed (step S143). The data of the arrival point set for the feature serving as the temporary destination is read (see FIG. 2), and the route search with the arrival point as the goal is performed. As described with reference to FIG. 2, the arrival point is the point where the main link data is reached either directly or by following any road from the entrance / exit line of the feature. It is possible to search for an appropriate route in consideration of the state of the road around the temporary destination.
When a feature for which no arrival point is set or a point unrelated to the feature is a temporary destination, a route search may be performed for a node at the shortest distance from the temporary destination.

Next, the navigation device 100 compares the routes for all temporary destinations and identifies the branch points of the routes (step S144). The method of identifying the branch point is shown in the figure. The following four routes are obtained as routes to each temporary destination.
Departure point-> Point BP1-> Point BP2-> Temporary destination D13 [20];
Departure point-> Point BP1-> Point BP2-> Temporary destination D13 [21];
Departure point-> Point BP1-> Point BP3-> Temporary destination D13 [22];
Departure point-> Point BP1-> Point BP3-> Temporary destination D13 [23];

By comparing these routes, it can be seen that all routes are common from the departure point to the point BP1. The navigation device 100 extracts the common part by comparing the links through the routes in this way. Then, a branch point where each route is divided, that is, a point BP1 is obtained in the example in the figure.
You can select a route that does not go too far to any temporary destination, that is, a route that does not increase the distance to the optimal route until the branch point, but after passing the branch point, the allowable range may be exceeded depending on the temporary destination. It is necessary to change the route beyond that. For example, in the example shown in the figure, after passing the branch point BP1 and proceeding in the direction of the point BP2, when going to the temporary destinations D13 [22] and D13 [23], it is necessary to return to the branch point BP1 once. Occurs, and the route becomes a large route. Thus, the branch point has a meaning as a limit point that can provide a route suitable for any temporary destination.
When the departure point is close to the destination area, there is a case where a common point is not found in the route to each temporary destination, and a branch point cannot be obtained. In such a case, the branch point cannot be set and the area designation route search process is terminated.

C3. Area-specific route guidance processing:
FIG. 14 is a flowchart of area route guidance processing. This process corresponds to step S150 of the route guidance process (FIG. 4), and performs route guidance using the result of the area designation route search process (FIG. 13) when the target area is designated.

  The navigation device 100 first inputs the route and branch point obtained by the area designation route search process (FIG. 13) (step S151). Then, the current position of the user is input (step S152). The current position can be detected by GPS or the like.

The contents of the guidance process differ depending on whether or not the current position of the user passes through the branch point. When a branch point is not obtained in the area designation route search process, it is treated as having passed the branch point.
When the current position does not reach the branch point (step S153), when the current position is in the vicinity of the branch point, that is, within a predetermined distance range from the branch point (step S154), the user is prompted to approach the branch. Guidance and prompt for input of destination (step S155).
This is because, if the vehicle goes beyond the branch point, the route must be changed beyond the allowable range depending on the destination.
Guidance for notifying the approach of a branch point can be a message display, a color change or blinking on a map screen, or voice guidance.
If it is not within the predetermined distance range from the destination, this process is skipped (step S154).

The navigation device 100 continues the route guidance regardless of whether or not the above-described guidance is performed (step S156).
FIG. 15 is an explanatory diagram of an area route guidance example (1). The current position of the user is the point PP15. In the area route guidance, since the destination is not uniquely specified, the navigation device 100 displays the map in a manner in which the correspondence relationship between the route and the destination can be identified.
In the example of the figure, the route branches at the node N34 ahead of the user, and when going straight in the direction of the link LW3, it is possible to go to the buildings HG to HJ, but it is necessary to change the route to the other buildings HA to HF. In this sense, the route in the link LW3 direction is a route associated with the buildings HG to HJ.
On the other hand, when turning left in the direction of the link LW4 at the node N34, it is possible to go to the buildings HA to HF, but a route change is necessary to go to the buildings HG to HJ. In this sense, the route in the direction of the link LW4 is a route associated with the buildings HA to HF.
The navigation device 100 displays a map so that the above-described association can be identified. In the example of the figure, the arrow A15a and the buildings HG to HJ attached to the route in the straight direction, and the arrow A15b and the buildings HA to HF attached to the route in the left turn direction are displayed in the same display form. The color may be changed such that the arrow A15a direction is red and the arrow A15b direction is blue, the arrow A15a direction is blinking, and the arrow A15b direction is always displayed. Here, an example in which the display mode is changed in two groups is shown, but the display mode may be divided into three or more groups depending on the route.
By doing so, the user can visually grasp which route he / she takes and which destination can be reached. Therefore, it is possible to select an appropriate route and proceed without specifying the destination again.

Returning to FIG. 14 again, the area route guidance process will be described.
When the current position of the user passes through the branch point (step S153), the navigation device 100 searches again for a route to the temporary destination that needs to be rerouted (step S157). What is necessary is just to judge that a reroute is required about the temporary destination from which the present position is removed from the path | route obtained with respect to each temporary destination.
The same applies when no branch point is obtained from the beginning. In this case, all temporary destinations are subject to reroute.

  For the temporary destination that has been rerouted, there should be a large roundabout from the route before the reroute. The navigation apparatus 100 calculates a large turning distance from the route difference between the routes before and after the reroute, excludes the temporary destination having the large turning distance of a predetermined distance or more from the guidance target (step S158), and guides the route to the remaining virtual destinations. Is performed (step S159).

FIG. 16 is an explanatory diagram of an area route guidance example (2). An example is shown in which a temporary destination where a large turn exceeding the allowable range occurs is excluded from the guidance target.
Consider the case where the user has passed through the node N34 as a branch point and proceeded straight on the link LW3 from the state shown in FIG. Since the buildings HG to HJ can be reached according to the conventional route, these buildings HG to HJ are guided and displayed in the same display manner as the arrow A16a in the straight traveling direction.
On the other hand, for the buildings HA to HF, as a result of the reroute, a route that returns the arrow A16b and proceeds on the link LW4 is obtained. If this route is compared with the previous route, i.e., the route that turns left at node N34 and enters link LW4 as indicated by arrow A16c, the route after reroute is the same as the link LW3 returns to node N34. It is a large turn.
Since this large distance exceeds the predetermined range, in the example shown in the figure, the buildings HA to HF are displayed in a display manner similar to that of normal features without any color or the like. In order to show that the buildings HA to HF are excluded from the destination, the display form with low visibility such as so-called grayout may be taken.
By doing so, the user can easily determine the correctness of the course that is proceeding by his / her own judgment by looking at the buildings remaining as guidance objects (buildings HG to HJ in the figure). Further, when specifying the destination by further narrowing down, it is possible to specify the destination within a range that does not cause unnecessary large turns.

FIG. 17 is an explanatory diagram of an area route guidance example (3). The case where the user further proceeds and comes to the current position PP17 is shown. At this point, since the building HJ is passed, the building HJ is excluded from the guidance target. The buildings HG to HI in front of you are guidance targets.
The navigation device 100 also reroutes the other buildings HA to HF in the destination area at this time. As a result, for the buildings HA to HD, a route traveling on the links LW2 and LW1 from the current position as indicated by the arrow A17a is obtained. This route is substantially the same as the route passing through the links LW4 and LW1 as indicated by the arrow A17b, so that the current position PP17 is not a large route exceeding the allowable range.
Therefore, the navigation device 100 displays the buildings HA to HD as guidance objects again.
As described above, even if the building is once excluded from the guidance target, it may be included in the guidance target again as a result of the movement of the current position. In this way, when the user notices a mistake in the route and corrects the course, the suitability of the corrected route can be easily determined depending on whether or not the intended destination is a guidance target. .

  In this way, in the area route guidance process, it is possible to support the user narrowing down and inputting the destination by the display (see FIG. 15) in which the route and the destination are associated with each other. In addition, when the user selects a route by his / her own judgment, it is possible to provide the user with information for determining whether the route is correct (see FIGS. 16 and 17).

D. Route guidance example:
FIG. 18 is an explanatory diagram showing an example of route guidance. According to the present embodiment, as shown in FIG. 18 (a), at the time of departure, it is possible to receive appropriate route guidance that does not cause a large turn even when a target area is roughly specified as in the area AR18a. The destination area may be narrowed down until the branch point BP18a for the destination area AR18a is reached.

Before reaching the branch point BP18a, the user performs input for narrowing down the range of the target area as shown in the target area AR18b of FIG. 18B. By doing so, the user can receive route guidance that does not cause a large turn. The user may further perform an input for narrowing down the target area before reaching the branch point BP18b for the target area AR18b.
When the user knows the location of the destination when he / she has reached the branch point BP18a, the route toward the destination may be advanced by his / her own judgment without narrowing down the destination area. As shown in the area guidance process (FIG. 14), since the navigation apparatus 100 excludes from the guidance target the range in which the over-rotation exceeds the allowable range due to the reroute, a narrowed area such as the target area AR18b is obtained.

  Before reaching the branch point BP18b, the user performs input for narrowing down the range of the target area as shown in the target area AR18c of FIG. By doing so, the user can receive route guidance that does not cause a large turn. In this way, the user can receive route guidance to the destination while inputting gradually narrowing down the destination area. Although an example of gradually narrowing down is shown here, an input for completely specifying the destination may be performed on the way.

  Further, when the user knows the location of the destination when he / she has reached the branch point BP18b, the navigation device can also be used when he / she travels the route toward the destination by his / her own judgment without narrowing down the destination area By 100, an area narrowed down like the target area AR18c is obtained. In the present embodiment, guidance that allows the user to reach the destination without making a round trip can also be performed by the method in which the user selects a route at his / her own judgment and proceeds.

The present invention does not necessarily have all the functions of the above-described embodiments, and only a part may be realized. Moreover, you may provide an additional function in the content mentioned above.
Needless to say, the present invention is not limited to the above-described embodiments, and various configurations can be adopted without departing from the spirit of the present invention. For example, a part configured in hardware in the embodiment can be configured in software and vice versa.

The present invention can also be configured as a route guidance method.
A route guidance method for guiding a route toward a designated destination by a computer having network data representing roads as nodes and links,
An input step of inputting a destination and a departure point in a state where the destination is not uniquely determined and leaves room for selection, and stored in a memory;
A temporary destination setting step of setting a plurality of temporary destinations used for route search within the range of the designated destination and storing them in a memory;
A route search step of searching for a route from the starting point stored in the memory to each temporary destination stored in the memory and storing the result in the memory with reference to the network data;
And a route guidance step of performing route guidance to a point where the route to each temporary destination stored in the memory branches.

Moreover, you may comprise as a computer program for implement | achieving this route guidance with a computer.
A computer program for guiding a route toward a specified destination by a computer having network data representing roads as nodes and links,
An input function that inputs the destination and departure point in a state where the destination is not uniquely determined and leaves room for selection, and is stored in a memory,
A temporary destination setting function for setting a plurality of temporary destinations used for route search within the range of the designated destination and storing them in a memory;
A route search function that refers to the network data, searches for a route from the starting point stored in the memory to each temporary destination stored in the memory, and stores the result in the memory;
A computer program for causing a computer to realize a route guidance function for performing route guidance to a point where a route to each temporary destination stored in the memory branches.

  The present invention can be used for route guidance in a state where a destination cannot be uniquely identified.

DESCRIPTION OF SYMBOLS 100 ... Navigation apparatus 101 ... Main control part 102 ... Transmission / reception part 103 ... Command input part 104 ... GPS input part 105 ... Map database memory | storage part 106 ... Display control part 107 ... Path | route search part 200 ... Server 201 ... Transmission / reception part 202 ... Database management Unit 210 ... Map database storage unit 211 ... Feature data 212 ... Character data 213 ... Network data

Claims (6)

A route guidance system for guiding a route toward a specified destination,
A map database storage unit for storing network data representing roads by nodes and links;
An input section for inputting a destination and a departure place in a state where the destination is not uniquely determined and leaves room for selection;
A temporary destination setting unit for setting a plurality of temporary destinations used for route search within the range of the designated destination;
With reference to the network data, a route search unit that searches for a route from the departure place to each temporary destination;
A route guidance system comprising: a route guidance unit that performs route guidance to a point where a route to each of the temporary destinations branches. The route guidance system according to claim 1,
The map database further stores feature data for drawing features including roads,
Referring to the network data and the feature data, it is a point on the road where the network data is maintained as a road on which a car can pass, and the road is directly or directly from the feature corresponding to the destination. An arrival point acquisition unit that acquires an arrival point that is a point that can be reached by passing,
The route search unit is a route guidance system that performs a route search using the arrival point as a temporary destination. The route guidance system according to claim 1 or 2,
The route guidance unit displays a map in a display mode in which a correspondence between each route and a destination reachable by the route can be identified for a portion after the route to each temporary destination is branched. system. The route guidance system according to any one of claims 1 to 3,
A current position input unit for inputting the current position of the user;
The route search unit extracts a temporary destination that can be reached from the temporary destination without changing the route when the current position is past a branch point where the route to each of the temporary destinations branches. ,
The route guidance system displays the extracted temporary destination in a display mode that can be distinguished from other temporary destinations. The route guidance system according to claim 4,
The input unit can input a designation of a destination or a specific destination narrowed down from the range after the input,
The route guidance system is a route guidance system that displays a map in a form in which a temporary destination whose route change exceeds an allowable range is excluded from targets of the specifiable destination. A route guidance system according to any one of claims 1 to 5,
It has a history storage unit that records the history of previous route search results,
The temporary destination setting unit refers to the history storage unit, and among the destinations in the previous route search result, those within a predetermined range from the designated destination are also designated as the designated destination. In addition to the route guidance system that sets a temporary destination.