JP2003207358A - Road guidance unit and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide users with guidance easier to understand by eliminating ambiguity in conventional route guidance data. <P>SOLUTION: For the preparation of departure-to-destination route guidance information based on map data containing road network data and landmark data, a user-designated route is picked out of the road network data and guidance points are extracted out of the same. Guidance data are then prepared for each of the guidance points and, in this process, the data are checked for ambiguity and the result is reflected in guidance data preparation for a reduction in ambiguity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route guidance device and a program for presenting a route from a starting point to a destination designated by a user on a map to provide route guidance.

[0002]

2. Description of the Related Art Conventionally, when performing route guidance, a route is searched from a database that stores map data based on road network data, and road shapes and intersection shapes are analyzed.
The guide information is generated by using the landmark selected from the database based on a certain selection criterion, the road shape and the intersection shape. As landmark selection criteria, for example, those that are more than a certain distance from the road are not presented, those that are near intersections are presented, or landmarks in a category with a high priority are presented preferentially. Has been.

However, when there is a similar intersection shape in the guide route or another road exists in a direction similar to the traveling direction, the user (for example, a pedestrian)
Sometimes took the wrong route. In addition, if only landmarks of a high priority category were presented preferentially, when walking along a national highway with few landmarks or in a residential area, there are few landmarks, and you may lose sight of turning points. Was there.

[0004]

As described above, in the conventional route guidance device, when there is a similar intersection or road shape, when a pedestrian is uncertain at which point to turn. Or, there is a possibility that the guide point indicated by the guide text may be wrong or may not be found.

The present invention has been made in view of the above circumstances, and a route guidance device and a program capable of eliminating the ambiguity of the conventional route guidance information and providing more user-friendly route guidance. The purpose is to provide.

[0006]

A route guidance device according to the present invention is a route guidance device for guiding a route from a starting point to a destination based on map data including road network data and landmark data. The route search unit that searches the route network data for a route from the starting point to the destination specified by, and extracts guide points along the searched route, and also provides route guide information about the extracted guide points. A route guidance information generation unit that generates the route guidance information, and generates the route guidance information based on the result of the verification so as to reduce the ambiguity of the guidance by verifying the ambiguity of the guidance regarding the guidance point when generating the route guidance information. An ambiguity verification unit for reflecting the information and a presentation unit for presenting the generated route guidance information are provided.

Further, the route guidance program according to the present invention is
A route guidance program for guiding a route from a starting point to a destination based on map data including road network data and landmark data, wherein the route from the starting point to the destination designated by a user is set to the road network. A route search step of searching from the data; a route guide information generating step of extracting guide points along the searched route and generating route guide information about the extracted guide points;
An ambiguity verification step of reflecting the result of the verification in the generation of the route guidance information so as to reduce the ambiguity of the guidance by verifying the ambiguity of the guidance about the guidance point when generating the route guidance information; And a presenting step of presenting the generated route guidance information.

According to the present invention, when the route guidance information generated at each guidance point of the route from the departure point to the destination is generated, the ambiguity of the guidance is verified, and if there is ambiguity, the ambiguity is detected. Since the verification result is reflected in the generation of the route guidance information so as to reduce, the user is not lost at the guidance point, and it is possible to provide the route guidance that is easier for the user to understand.

Here, the route guidance information generating unit generates route guidance information including a route pattern of the guide points generated based on the map data and landmarks near the guide points included in the map data. . The guidance point refers to a point to be guided from the starting point to the destination, such as a point where the road is turned at an intersection or the like, a point where the shape of the road continues, or a point where the road is crossed. The route pattern refers to, for example, an intersection shape, a road shape, a footbridge shape, or the like. A landmark is a landmark on the route, such as a building, a signal, a post, a public telephone, a park, a bus stop, or the like.

The ambiguity verification unit analyzes the route pattern around the guide point based on, for example, map data and determines whether or not a route pattern similar to the route pattern of the guide point exists around the guide point. It consists of a pattern determination unit. In this case, the route guidance information generation unit
When the similar pattern determination unit determines that there is a similar route pattern, the similar pattern and the guide point route pattern are used to determine, for example, “the second T-shaped of two T-shaped paths”. Turn right on the road. "Is generated to generate the road guidance information semantically including the existence of a similar route pattern around the guide point.

Further, the ambiguity verification unit may be composed of a route verification unit for verifying whether or not the route is uniquely determined from the route guidance information generated by the route guidance generation unit.
For the landmarks included in the map data, when the presentation priority is determined, the route guidance information generation unit initially generates the route guidance information using only the landmarks with high priority of presentation, The route guidance information for which the route is not uniquely determined by the route verification unit is regenerated from the map data so as to include a landmark having a priority lower than the priority of the original presentation in the vicinity of the guide point. This allows
If the route can be uniquely determined, the ambiguity of the route guidance is reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a route guidance device according to an embodiment of the present invention. Database 1 contains
Basic data for generating a guide route, a guide sentence, and a simplified map along the route, such as a map database, a guide sentence database used to generate guide sentences as guide information, and a simplified map database. Has been accumulated. The map database includes road network data and landmark data. The database 1 may be provided in the route guidance device as described above, but when the function of the route guidance device is implemented in a mobile communication terminal such as a mobile phone or a PDA, or the route guidance device is a dedicated portable type. When configured as a device, it may be provided outside the route guidance device and connected to the route guidance device by a wireless communication path. In addition, the map database of the database 1 may be an external database provided outside the route guidance device, and the remaining route guidance sentence database and simplified map database may be configured as internal databases to be provided inside the route guidance device. .

The user input unit 2 is used by a user who uses the route guidance device, that is, a pedestrian to perform various input operations by key operations or dial operations. When the user inputs the position information of the departure point and the destination through the user input unit 2, the road network data is read from the database 1 based on these position information, and the route searching unit 3
Passed to.

In the route search unit 3, the departure place based on the position information of the departure place and the destination input by the user input unit 2 and the road network data read from the database 1 corresponding to these position information. From the destination to the destination is searched, and route data representing this route by, for example, vector data is generated.

The similar pattern analysis unit 4 constitutes an ambiguity verification unit according to the present invention. The similar pattern analysis unit 4 corresponds to the route data from the route search unit 3 and the roads and landmarks around the route. The situation of the route is analyzed, and the information on the situation around the route is generated. Here, the route peripheral situation analysis is a process of determining whether the peripheral situation of the position selected as the guide point is easy for the user to understand, and as will be described later in detail, an intersection of similar shapes is formed near the guide point. Is there a T-junction or a Y-junction so that the user will not hesitate or
There are no more recognizable landmarks in the front or the back, or there is insufficient information to check the route while the pedestrian walks because the guide point is too far away from the guide point, etc. It is an analysis of the situation. For specific analysis method of the situation around this route,
It will be described in detail later.

[0016] A guide text generation unit 5 and a simplified map generation unit 6
Then, at least the surrounding situation from the similar pattern analysis unit 4 and the landmark data read from the database 1 in correspondence with the route data from the route search unit 3 are used to indicate the route data from the route search unit 3. As guidance information for guiding the user along the route, data of a guidance sentence and a simplified map are generated.

The presenting unit 7 comprises a display or a display and a speaker. In the presenting unit 7, the route guidance sentence is presented in a character string or a voice or both based on the route guidance sentence data from the route guidance sentence generating unit 5, and further based on the simplified map data from the simplified map generating unit 6. A simple map along the route from the origin to the destination is displayed as an image. As a result, these guide texts or simplified maps are presented to the user.

Among the components of the route guidance device of FIG. 1 described above, a part of the database 1, a route search unit 3, a similar pattern analysis unit 4, a route guidance sentence generation unit 5 and a simplified map generation unit 6 are provided.
Can be realized by software processing by a computer incorporated in a device such as a route guidance device terminal or a mobile communication terminal.

Next, the procedure of the route guidance process in this embodiment will be described with reference to the flowchart shown in FIG. First, a user who desires route guidance operates the user input unit 2 to input a departure place and a destination (step S101). This input operation is performed in a state where a map of a place of departure and / or a destination including one of them is displayed on the display screen of the route guidance device, that is, the display screen of the presentation unit 7 based on the map database of the database 1. You can specify the starting point and destination using the mouse, cursor, pen, keys, etc. on the map, or select the starting point and destination from the list of landmarks, address names, etc. You may go by

Next, the route search unit 3 searches for a route from the departure place to the destination according to the departure place and the destination and the route search condition input by the user (step S10).
2). As a route search method, a method such as preferentially selecting a route with a sidewalk can be considered. For example, the method of Dijkstra known as an algorithm for solving the shortest route can be used. Of course, other route search methods can be used, and in short, any route connecting the starting point and the destination can be searched. In some cases, the user may directly specify the route.

As a result of this route search, route data represented by a node N and an arc A from a starting point to a destination as shown in FIG. 3 is obtained. The node N and the arc A can be expressed by items as shown in (a) and (b) of FIG. 4, for example. The node N is a branch point of the road network and exists at, for example, an intersection or a corner. Each node N includes an ID (numerical value), a position (X, Y), a name (character string), the number of arcs to be connected (numerical value), an array of arc IDs to be connected (numerical value array), and the like. The arc A is a line connecting the nodes N and N, and has an ID (numerical value), a start point position (X0, Y0), an end point position (X1, Y1),
It consists of a name (character string) and road width (numerical value).
When a plurality of arcs A are present in one node N, a plurality of arc groups connected to the node N can be extracted, or a series of roads can be obtained by tracing from arc to node and from node to arc. You can trace the route.

Here, the guide point refers to a case of turning a road at an intersection or the like, or a case where the shape of the road continues along the road.
When crossing a road, it is a point that serves as a mark necessary to reach the route from the departure point to the destination without mistake, and the guide point guides the target at the same time. Targets are buildings such as banks and supermarkets that tend to be landmarks, signals, names of intersections, names of roads,
It refers to road shapes such as T-shaped roads and intersections, incidental items to roads such as pedestrian bridges and pedestrian crossings, and all that can be used as landmarks when pedestrians walk. The route search unit 3 can acquire information on these targets by referring to the road network data and the landmark data in the database 1.

Next, the guide text generating unit 5 uses the landmark data accumulated in the database 1 and the guide text database included in the database 1,
A guide text including a road shape description and a landmark name for guiding the user along the route searched in step S102 is generated (step S103). At this time, at the same time, the similar pattern analysis unit 4 performs step S
The situation around the route searched in 102 is analyzed (step S103). The route peripheral situation here is mainly a road shape near the guide point. When the guide point is an intersection, for example, what kind of intersection the shape of the intersection is, a road in the approach direction and a road in the exit direction. It refers to the shape of a road that cannot be analyzed only by road network data, such as how many angular differences or whether it intersects a thick road at an intersection. The similar pattern analysis unit 4 analyzes the situation around the route of the guide point and analyzes whether or not there is a similar road shape when guiding the point. The guide sentence generation unit 5 generates a guide sentence with no ambiguity, based on the route surrounding situation data obtained by the similar pattern analysis unit 4 (step S103).

Further, in the present embodiment, the simplified map generation unit 6 includes the route peripheral situation data obtained in step S103, the information (for example, target information) obtained by the route guidance sentence generation, and the database 1 in the simplified map generation unit 6. A simplified map is generated using the simplified map database (step S10).
4). Then, the presentation unit 7 presents the route guidance sentence generated in step S103 in a character string and / or voice display, and also presents the simplified map generated in step S104 by image display (step S1).
05).

Next, the contents of specific steps in the flowchart of FIG. 2 will be described in detail. FIG. 5 shows a similar pattern analysis / guidance sentence generation process (step S10) of FIG.
It is a flow chart which shows the details of 3). When generating the route guidance sentence, first, the route search unit 3 performs step S10.
The route data generated in 2 is simplified (step S201). The simplification process consists of two processes: deletion of short line segments and merging of continuous line segments in the same direction. The deletion of the former short line segment is different from the actual traveling direction of the road in order to maintain the connection of the road network at the intersection of large roads, the part where the median strip, the overpass, etc. appear on the road. This is a countermeasure against the case where short line segments are mixed. The latter merging process reduces the amount of guide texts without significantly reducing the amount of information by merging line segments that mean the progress in the same direction with each other in order to generate guide texts in arc units. It is done for the purpose. In FIG.
An example in which the route of is simplified is shown. In this example, 6 nodes N1 to N6 from the departure point to the destination point are connected 5
Of the two arcs A1 to A5, the arcs A2 and A3 are merged into an arc A2 ', and the number of arcs is simplified from five to four. By performing such a simplification process of the route data, the guide points P are narrowed down to four places. This facilitates the process of generating a guide text and a simplified map along the route.

Next, similar pattern analysis processing is executed by the similar pattern analysis unit 4 (step S202). As a specific example of this processing, processing for analyzing the shape near the intersection will be described. The similar pattern analysis unit 4
The road network data in the route searched by the route search unit 3 is extracted from the database 1 and, for example, as shown in FIG. A size mask (indicated by a dotted line in the figure) is prepared, and the road network data is cut out as a target of route peripheral situation analysis using this mask.

Next, the road network data included in the area (road network cut-out area) cut out using this mask is subjected to pattern analysis, and a road extending from the intersection to the outside of the road network cut-out area as shown in FIG. Number of lines n
(N = 4 in this example), and the direction (angle difference from the approach direction) and width of each road line segment are measured. By such pattern analysis of the road shape, the target intersection is determined to be “a four-fork intersection”, “a T-shaped collision”, “a Y-shaped three-fork intersection”, or the like.

Next, the similar pattern analysis unit 4 searches for another intersection near the guide point along the traveling direction, for example.
FIG. 9 shows an example in which two T-shaped intersections are located near the guide point and the intersections of the L-shaped road and the crossroads other than that.

Next, the landmarks along the route simplified in step S203 are extracted (step S202). The database 1 shown in FIG.
Landmark data consisting of items such as 0 is stored for each landmark. In FIG. 10, "I
“D” is a numerical value that represents the landmark identifier. The “name” is the name of the landmark and is a character string such as a store name and a facility name. The “type” is a numerical value (code) representing the type of landmark such as a gas station or a bank. The “priority” is a numerical value used as an evaluation criterion for whether or not to preferentially use the route search or the generation of the guide text. "Position" is the landmark X, Y
The coordinates (eg, latitude and longitude).

In step S203, landmark data of landmarks along the simplified route necessary for route guidance are selected from the landmark data shown in FIG. 10 for each landmark stored in the database 1. Perform the process to extract only. Next, the route data simplified in step S201, the analysis result obtained in step S202 by the similar pattern analysis unit 4, and step S2.
A unit guidance sentence is generated using the landmark data extracted in 03 (step S204). The unit guidance sentence is, for example, (1) a sentence that guides from the starting point to the first target object, (2) a sentence that guides from the target object to the next target object, and (3) from a corner to the target object. It is a minimum unit that can be divided as a sentence when giving directions to a pedestrian, such as a sentence that provides guidance for (4) and a sentence that provides guidance from a target object to a destination. The unit guidance sentence can be generated, for example, by using the distance from node to node and the state of landmarks, intersections, and corners in the vicinity thereof. In particular, when the target object is an intersection, it is determined whether the shape of the intersection is a three-forked road (T-shaped road, Y-shaped road), four-forked road, and how to proceed the four-forked road. Since it is possible to guide based on the information obtained by, it is possible to generate easy-to-understand sentences.

Finally, in step S205, the generated unit guidance sentences are combined along the route. Accordingly, it is possible to generate a guide text that guides the route from the departure place to the destination in a series of sentences. For example, when creating a guidance sentence along the route of FIG. 9,
The example of the guide text generated in the prior art and the guide text generated based on this embodiment is shown. Figure 1
In the route guidance sentence of 1 (b), the underlined portion is a sentence peculiar to this embodiment that is not shown in FIG. 11 (a). That is, in the sentence on the third line of the route guidance sentence in FIG. 10 (a), only "Turn left at the T-junction and proceed 50 m." Is presented. Therefore, which of the two T-junctions shown in FIG. Pedestrians are wondering if they should turn left at the T-junction of
In the guide text of (b), "a place with two T-junctions,
Turn left at the second T-junction. ”, It is clear that there are similar shaped intersections nearby, so
Pedestrians can turn to the right T-junction. Also,
In this example, as shown in FIG. 10 (b), the guidance text of the guidance point that is particularly apt to be mistaken is underlined and highlighted, so that the pedestrian can be alerted and further mistakes occur. It is designed so that it does not exist.

Next, a simplified map generation process (step S10)
4) will be described. In this example, the database 1 corresponds to various road shape data obtained by the route surrounding situation analysis in order to generate a simplified map.
Presentation patterns as shown in (a), (b), (c), and (d) are registered in advance as an expression model. This expression model is obtained by registering various presentation patterns shown in FIGS. 12 (a), (b), (c), and (d) as vector data in the simplified map database in the database 1, and is used for expressing a simplified map. To be done.

FIG. 13 is a detailed flowchart of the simplified map generation process. When generating the simplified map, first, an expression model composed of vector data corresponding to the road shape data generated by the similar pattern analysis unit 4 is selected from the database 1 (step S301).

Next, the landmark data around the route is extracted from the database 1 (step S302). When the target landmark data is extracted in step S302, information such as the landmark name, intersection name, and distance from the intersection is inserted into the corresponding expression model to generate a guide route (step S303).

Next, the expression model (presentation pattern) consisting of vector data obtained corresponding to each intersection etc. is connected along the guide route generated in step S303 (step S304), and further shaped. The generation of the simplified map is completed by generating the map from the starting point to the destination along the guide route (step S306).
Prior to the generation of the nest, the analysis result of the similar pattern analysis unit 4 is fetched (step S305), and this is reflected in the generation of the simplified map, so that there is ambiguity as shown in FIG. 14, for example. It is also possible to perform emphasis display for calling attention.

In this way, the presentation pattern consisting of vector data for a simplified map corresponding to various patterns of the road shape data generated by the similar pattern analysis unit 4 is registered in the database 1 in advance as an expression model, By combining the expression models corresponding to the road shape data actually obtained by the similar pattern analysis unit 4, it is possible to easily generate a simplified map along the guide route. In this case, unlike the previous example, the presentation pattern, which is an expression model, is compared with the bitmap data, and the database 1 is used as vector data having a significantly smaller data amount.
Since it is stored in the database, the load on the database 1 is reduced, the processing amount of the route guidance device is also reduced, and the speed can be increased. In addition, when vector data is used, it is easy to perform shaping such as removing unnecessary information from the simplified map as described above, so especially when performing directions with a device with a small display screen such as a mobile communication terminal. However, there is an advantage that a simple map that is easy to see can be presented to the user. Of course, another method may be used as the method of generating the simplified map.

Next, a route guidance device according to another embodiment of the present invention will be described. FIG. 15 is a block diagram showing the configuration of this device. In this device, the route verification unit 8 is used as the ambiguity verification unit instead of the similar pattern analysis unit 4 shown in FIG.
Is equipped with. The route verification unit 8 verifies whether the route is uniquely determined from the route guidance information generated by the route guidance generation unit 5. The route guidance generation unit 5 reflects the verification result of the route verification unit 8 on the generated route guidance information.

FIG. 16 is a flow chart showing the main part of the route guidance processing of this device. This process is a process in the route guidance sentence generation unit 5 and the route verification unit 8. When a pedestrian walks according to the generated route guidance sentence, it is determined whether or not the road to be the route is uniquely determined, and If there is a road with the specified shape or the landmarks are vague and the designated route cannot be clearly determined, the landmark or route shape information should be changed or added so that the pedestrian can be determined. , This is a process for providing more understandable directions.

In the guide sentence generation in step S401, the route verification unit 8 selects 1 from the guide sentence obtained by the guide sentence generation unit 5.
Take out the guidance sentence by sentence. Step S402 is to confirm the end of the process while the generated route guidance sentence is being processed one by one. In step S403, it is determined whether the route is uniquely determined by tracing the road network from the obtained route guidance sentence. For example, an example of turning right at the target intersection in FIG. 17 will be described. FIG. 18 is an enlarged view of the target intersection A in FIG. In the guide text generating unit 5, the pedestrian's traveling direction can be defined as shown in FIG. 19, for example, and in FIG. 18, θ1 is the angle formed by roads and θ2 is the road's roads. Indicates the angle to make. In the example of FIG. 18, the traveling direction when traveling from road to road is a right turn according to the table shown in FIG. Therefore, the guide text obtained here is, for example,
"Please turn right at the crossroad with a convenience store." Is output.

Next, in step S403, it is determined whether or not there is a route that can be determined from the expression obtained in step S401 on the route in the traveling direction. This is whether or not the indicated landmark can be found, or when the explanation of the direction of travel is replaced by the general terms such as right turn, straight ahead, left turn, depending on the angle between the approach road and the road in the direction of travel, This is to determine whether or not there is a road that says the same.

For example, FIG. 21 shows an example in which an angle is defined for each direction. Right turn is defined as 60 ° <θ1 and θ2 <120 °, and if this is searched again for roads and roads within the range (60 ° to 120 °) as shown in FIG. 20, in this example, Roads and roads are candidates. Therefore, in this sentence, two road candidates to be advanced have appeared.

Next, in step S404, another landmark is extracted as the information for determining the route. Figure 2
2 is an example of the priority of landmarks. In the guide text, the landmark with the highest priority is extracted, so a convenience store is selected, but the priority for extracting landmarks is lowered. And in the example of FIG. 17, in addition to this,
It can be seen that the post and payphone exist, and the road that is the road in the route is the road between the post and payphone. Therefore, finally, the guide text is generated again in step S401 using the newly discovered landmark information.

In this way, the process of steps S401 to S404 is repeated for one sentence, and the verification is repeated until the user can uniquely determine the route. At this time, since there may be no landmark, in that case, the shape of a nearby road or the shape of an intersection may be added to the expression, or it may be specified that there is no conspicuous building. In other words, pedestrians are walking and can reliably determine the road shape and landmarks that serve as landmarks,
It suffices if the route can be presented so as not to make a mistake.

As a result of carrying out such processing, as shown in FIG. 23, in the conventional guide text, as shown in FIG. 23A, only "turn right at a crossroad with a convenience store 50 m ahead". The route was not presented and the route was not uniquely determined. On the other hand, in FIG.
"At the crossroad with a convenience store 50 meters ahead, turn right on the road between the public telephone and the post." Therefore, the route is uniquely determined and pedestrians will not get lost. As described above, according to the route guidance device of the present embodiment, since the route guidance sentence is presented based on the complexity of the route, it is possible to provide easy-to-understand route guidance.

Even if the guide text is not generated, in the example of FIG. 17, the number of landmarks displayed on the map is increased, such as changing from the display of the convenience store alone to the display of post and public telephone. This makes it possible to obtain a map that is easier to understand.

[0046]

As described above, according to the present invention, the ambiguity of the guidance is verified when the route guidance information is generated at each guidance point of the route from the departure point to the destination.
When there is ambiguity, the verification result is reflected in the generation of the guidance information so as to reduce the ambiguity.
The user will not get lost at the guidance point, and it becomes possible to provide more user-friendly route guidance.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a route guidance device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of a route guidance process in the same embodiment.

FIG. 3 is a diagram showing an example of a route searched for.

FIG. 4 is a diagram showing an example of the structure of nodes and arcs that form route data.

FIG. 5 is a flowchart showing a flow of a route guidance sentence generation process in FIG.

FIG. 6 is a diagram showing an example of a simplified route.

FIG. 7 is a diagram showing an example of analysis of road network data and intersection shapes in the vicinity of an intersection.

FIG. 8 is a diagram illustrating various parameters representing an intersection shape.

FIG. 9 is a diagram showing an example of analyzing the shape of an intersection in a route.
Try.

FIG. 10 is a diagram showing an example of landmark data.

FIG. 11 is a diagram showing an example of a guide text generated by the same embodiment in comparison with an example of a guide text based on a conventional technique.

FIG. 12 is a diagram showing an example of a presentation pattern corresponding to various road shape data for generating a simplified map registered in a database.

13 is a flowchart showing a flow of a simplified map generation processing example in FIG.

FIG. 14 is a diagram showing an example of highlighting points that are likely to be erroneous on a simplified map.

FIG. 15 is a block diagram showing a configuration of a route guidance device according to another embodiment of the present invention.

FIG. 16 is a flowchart showing a flow of route peripheral situation analysis processing in the apparatus.

[Fig. 17] Fig. 17 is a diagram for explaining an intersection situation for explaining in detail how to provide ambiguous expressions by route situation analysis.

FIG. 18 is a diagram for explaining how to select an expression from a road angle difference from an approach direction to a traveling direction.

FIG. 19 is an example in which a direction expression is defined for each angle.

FIG. 20 is a diagram for explaining determination of ambiguity from a road progression expression from an approach direction to a traveling direction.

FIG. 21 is an example in which an angle is defined for each directional expression.

FIG. 22 is a diagram showing an example of priority order of landmarks.

FIG. 23 is a diagram showing a conventional example (a) and a present example (b) of a generated route guidance sentence.

[Explanation of symbols]

1 ... Database 2 ... User input section 3 ... Route search unit 4 ... Similar pattern analysis unit 5 ... Direction sentence generator 6 ... Simplified map generator 7 ... Presentation section 8 ... Route verification unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroaki Kubota             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center F-term (reference) 2C032 HB25 HC11 HD21                 2F029 AA02 AB13 AC02 AC09 AC14                       AC19                 5H180 AA01 FF14 FF23 FF27 FF33                       FF38

Claims (7)

[Claims] 1. A route guidance device for guiding a route from a starting point to a destination based on map data including road network data and landmark data, the route from the starting point to the destination designated by a user. A route search unit that searches from the road network data; a route guidance information generation unit that extracts guidance points along the searched route and generates route guidance information about the extracted guidance points; An ambiguity verification unit that verifies the ambiguity of the guide about the guide point and reduces the ambiguity of the guide when generating the guide point; A route guidance device comprising: a presentation unit that presents guidance information. 2. The route guidance information generation unit generates route guidance information including a route pattern of guide points generated based on the map data and landmarks near the guide points included in the map data. The route guidance device according to claim 1, wherein 3. The ambiguity verifying unit analyzes a route pattern around the guide point based on the map data to determine whether a route pattern similar to the route pattern of the guide point exists around the guide point. A similar pattern determination unit that determines whether the route guidance information generation unit, if the similar pattern determination unit determines that there is a similar route pattern, the similar route pattern and the guide point route pattern The route guidance device according to claim 1 or 2, wherein the route guidance information is generated by using. 4. The route guidance device according to claim 3, wherein the route pattern for which the similar pattern determination unit determines similarity is an intersection shape. 5. The route guidance information generation unit is configured to generate route guidance information semantically including the presence of a similar route pattern around the guidance point. The described route guidance device. 6. The ambiguity verification unit includes a route verification unit that verifies whether or not a route is uniquely determined from the route guidance information generated by the route guidance generation unit, and is included in the map data. The priority of presentation is determined for the landmark, and the route guidance information generation unit initially generates the route guidance information using only the landmark of high presentation priority, and the route verification unit generates the route. The route guidance information that was not uniquely determined is regenerated from the map data so as to include landmarks having a priority lower than the priority of the initial presentation in the vicinity of the guide point. The route guidance device according to claim 1 or 2. 7. A route guidance program for guiding a route from a starting point to a destination based on map data including road network data and landmark data, wherein the route from the starting point to the destination designated by a user. A route searching step of searching for a route from the road network data; a route guidance information generating step of extracting guidance points along the searched route and generating route guidance information about the extracted guidance points; An ambiguity verification step of reflecting the result of the verification in the generation of the route guidance information so as to reduce the ambiguity of the guidance by verifying the ambiguity of the guidance about the guidance point when generating the guidance information; And a presenting step of presenting the route guidance information, which causes the computer to execute the presenting step.