JP2008215858A - Navigation device, navigation system, and route display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device for rapidly screen displaying a summary map easy for a user to understand even if connection relations of a plurality of routes searched for are complicated, a navigation system, and a route display method. <P>SOLUTION: A plurality of routes are found from map data. With bifurcations and confluences of the plurality of routes used as nodes, the respective routes are defined by extension links together connecting these nodes. Thereafter, according to prescribed link unification conditions, a plurality of links in a specific detour section are unified into one link, thereby further simplifying route data. Based on the simplified route data, an optimum route is expressed by using a straight line while the remaining routes are expressed by using broken lines. The summary map is produced in a form where both ends of each broken line are connected to bifurcations or confluences on another route, and what is obtained by adding traffic state information and textual information including road designations to the summary map is displayed as a route schematic on a navigation screen. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to navigation technology, and more specifically, a navigation device that searches a plurality of routes from a current location or a point designated by a user to a destination, and presents these routes in a map form that is easy for a user to understand. The present invention relates to a navigation system and a route display method.

  The navigation device has a candidate route display function that searches a plurality of routes to a purpose set by the user, displays an overall view of these routes as candidate routes, and allows the user to select one of them as an initial route. Yes. In addition, a navigation device having a function of searching for a detour under different search conditions according to a traveling road condition and displaying a plurality of searched detours during route guidance according to an initial route selected by the user is known. It has been.

  For example, in Japanese Patent Laid-Open No. 2003-214879 (Patent Document 1), a plurality of searched candidate routes are displayed on a map screen, and associated with each route, an estimated required time, a travel distance, A navigation device that displays character information such as a fee is disclosed. Japanese Unexamined Patent Application Publication No. 2004-347420 (Patent Document 2) discloses a navigation device that presents a plurality of searched candidate routes as a summary map on a screen. Patent Document 2 proposes a method of converting a plurality of searched candidate routes into a summary map that is easy for the user to view by performing deformation processing such as straightening or orthogonalizing a road shape.

JP 2003-214879 A JP 2004-347420 A

  However, in the navigation device disclosed in Patent Document 1, a plurality of searched candidate routes are displayed on the screen in their original shapes, so that it is difficult to distinguish between routes, road branch points, and junctions. There is a problem. On the other hand, in the navigation device disclosed in Patent Document 2, since a plurality of candidate routes are presented on the screen as a summary map, it is easy for the user to sort the plurality of routes. However, in Patent Document 2, on the summary map, a plurality of routes are gradually deformed based on the respective road shapes so that there is no contradiction in the connection relationship between the links that are the components of the route. There is a problem that the deformation process takes time.

  On the other hand, paying attention only to the connection relation of a plurality of searched routes, a method of arranging nodes including branch points and junctions and links connecting the nodes on a grid at equal intervals can be considered. According to this method, a summary map can be generated with much less calculation time and memory consumption than a method of deforming based on the shape of a plurality of routes. However, when the number of branch points and merging points is large, the connection relationship is complicated, so that the summary map is not always easy for the user to understand.

  An object of the present invention is to provide a navigation device, a navigation system, and a route display method capable of promptly displaying a summary map that is easy for a user to understand even when the connection relationship of a plurality of searched routes is complicated.

  In order to achieve the above object, in the present invention, a route section divided by these nodes is newly created from the route data indicating the plurality of routes searched from the map data, with the branch points and the junctions of the plurality of routes as nodes. By generating route data as links and integrating a plurality of links in a specific detour section into one link according to a predetermined link integration condition, the route data is further simplified, and the route data is simplified. Based on this summary map, the optimal route is represented by a straight line, the rest of the route is represented by a polygonal line, and both ends of each polygonal line are combined with branching points or junctions on other paths. In addition, traffic route information and character information including a road name are added to the navigation screen and displayed as a route schematic diagram.

  In the original route data, a number of links are defined along the route, with road intersections and branch points as nodes. In the present invention, since the nodes and links are redefined based on the connection relationship between the plurality of routes to be displayed in the route schematic diagram, each route includes a plurality of links including the plurality of links indicated by the original route data. Defined with a link extended to Further, by integrating a plurality of links in a detour section that satisfies the link integration condition, each route is defined by route data that is further simplified.

  In one embodiment of the present invention, in response to a user operation, it is possible to display a route schematic diagram selectively reproducing a detour of a link integrated section that is hidden on the display screen. The route simplification by link integration is executed in order from the detour section with the lowest display importance among the detour sections satisfying the link integration condition, and conversely, the reproduction of the link integration section is the detour with the higher display importance. It is executed in order from the section.

  According to the present invention, the link sequence of each route is redefined according to the connection relation between the plurality of searched routes, and the optimum route is displayed as a straight line based on the simplified route data, and the remaining routes are displayed. Since it is displayed as a broken line, it is easy to generate a summary map. In practice, a plurality of routes having complicated shapes can be quickly provided as a simplified route schematic on the display screen. In addition, since the summary map is simplified by integrating multiple links of the detour part with low importance at the time of route selection into one link, route information such as traffic jam information and road names on the summary map Information can be easily displayed, and the user can easily grasp the outline of the candidate route.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an embodiment of a navigation system to which the present invention is applied.
The navigation system includes a navigation device 10 mounted on an automobile and a traffic information distribution server 30 connected to a communication network NW. A plurality of radio base stations 20 are connected to the communication network NW, and the navigation apparatus 10 is connected to the communication network NW via the radio base station 20, and traffic information such as congestion information described later is transmitted from the traffic information distribution server 30. Get traffic information.

  The navigation device 10 includes a control unit 100 that controls the entire device, a map data storage unit 102 that stores map data, a current position acquisition unit 103 that acquires position information of the vehicle by a GPS sensor, and the like. An input unit 104 that receives input, a display unit 105 that displays a user operation screen and a map, and a wireless communication unit 106 that communicates with the traffic information distribution server 30 via the wireless base station 20 and the communication network NW20. . Although omitted in FIG. 1, the navigation device 10 may include a voice output unit that gives guidance information to the user by voice in conjunction with information presentation to the screen display unit 105.

The control unit 100 includes a processor 101 and a memory 107.
The memory 107 includes, as program software related to the present invention executed by the processor 101, an input reception control unit 110 that receives input information such as a destination input from the input unit 104 by a user operation, a departure point setting, and a destination A route guidance control unit 111 that controls display contents and route guidance according to the state of the navigation device, such as setting, initial route selection, route guidance, etc., and a map data storage unit when the user sets a destination Referring to 102, a route search unit 112 that searches for a plurality of candidate routes from the departure point (or current position) to the destination, and generates a route schematic diagram for initial route selection from the plurality of searched candidate routes. Then, a route schematic diagram generating unit 113 that outputs to the display unit 105 and a plurality of route search conditions 115 (115-1 to 115-1) to be used by the route searching unit 112. 5-n) and the route search condition setting section 114 for setting are prepared.

  The map data storage unit 102 is configured by a hard disk drive or a DVD (Digital Versatile Disk) drive having a relatively large capacity recording medium. The input unit 104 includes, for example, a touch panel and operation buttons, and the display unit 105 includes a display screen such as a liquid crystal display and an audio output device such as a speaker. The memory 107 includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The programs 110 to 104 are stored in the ROM, and the map data read from the route search condition 115 and the map data storage unit 102 are: Stored in RAM.

  Here, although the navigation apparatus 10 that receives traffic information from the traffic information distribution server 30 via the network NW is shown, the present invention accesses, for example, a Web (World Wide Web) server via the network NW, The present invention can also be applied to a communication type car navigation apparatus having a function of enjoying various Web services.

FIG. 2 shows a configuration example of the navigation map database 40 stored in the map data storage unit 102.
The map database 40 includes map display data 41, route calculation data 42, and link correspondence data 43. The map display data 41 is data for defining a map displayed on the display screen, and is composed of road data 401, background data 402, and character data 403.

  As described in detail in FIG. 4, the road data 401 describes each road by a combination of a plurality of nodes serving as end points or branch points and links connecting two adjacent nodes. The shape of the road is represented by the coordinates of a shape interpolation point located at a key point in each link.

  The background data 402 includes data serving as the background of a road map such as railways, rivers, and buildings, and the character data 403 includes a note character string displayed on the map such as a place name, a road name, and an intersection name.

  The route calculation data 42 describes a route (node network) by a combination of a node and a link, and can express a cost (required time and fee) between nodes and links. The link correspondence data 43 is for associating each link with another data block, for example, a data block indicating traffic jam information acquired from the traffic information distribution server 30.

  Node IDs (identifiers) and link IDs are assigned to the nodes and links that define each road, respectively. Each link is associated with another data block such as a traffic jam information data block, a road shape data block, and a name data block, for example, by a link ID.

  The map data for car navigation includes route guidance data indicating signboards and driving lanes output at the time of route guidance, guidance search data used for POI search and address search, etc. Since the data is not related to the present invention, the detailed description is omitted.

FIG. 3 shows a hierarchical structure of map data stored in the map data storage unit 102.
In the car navigation device, the map display data 41 and the route calculation data 42 shown in FIG. 2 are managed in several scale levels in order to manage the map data according to the scale. The map data at each level is managed for each mesh by dividing the map area into a plurality of meshes along the latitude and longitude.

  FIG. 3 shows the relationship between the level L (i) and the upper level L (i + 1), L (i + 2) mesh with the level L (i) indicating the most detailed map as the lowest level. As indicated by the diagonal lines, the map data at the level L (i) indicates an enlarged map of one mesh at the upper level L (i + 1), and one mesh at the level L (i + 2) indicates the lower level L (i + 1). The scale map which integrated the some mesh (in FIG. 2, 16 mesh) is shown.

  The route calculation data 42 includes data for associating the levels described above. Further, data distributed from the traffic information distribution server 30 to each navigation device, for example, data indicating a traffic jam area is associated with at least one of the plurality of levels described above.

  The route search unit 112 of the present invention searches the map data storage unit (map database) 102 for a plurality of routes from the current location to the destination according to the route search condition 115, and from the traffic information distribution server 30 in these routes. Get traffic information. The route data indicating the search result is output after converting the level so that it can be associated with the distribution data from the traffic information distribution server 30.

FIG. 4 is a diagram illustrating an example of a basic configuration of the road data 401.
The road data includes nodes n (n1 to n4) indicating feature points such as branch points and intersections, and links a (a1 to a5) indicating road sections connecting the nodes. In the road data, a point called a shape interpolation point is set in the middle of a link in order to express a road shape between nodes. In FIG. 4, sections a1 to a5 indicated by broken line arrows are links, and black circles p1 to p10 represent shape interpolation points.

  The route search condition 115 used by the route search unit 112 of the navigation device 10 is provided with a plurality of search conditions with different parameters to be regarded as important, such as required time priority or distance priority. . In the route search condition with the required time priority, as the traffic information to be applied to the required time calculation, the statistical traffic information stored in the internal memory in advance and the real-time traffic information dynamically received from the traffic information distribution server 30 are used. Either one can be selected.

  The route search unit 112 calculates the cost of each link shown in FIG. 4 in accordance with the route search condition 115 specified by the user. For example, based on the route search method such as the Dijkstra method, the route search unit 112 calculates the cost of each link. A route with the lowest link cost to the end node (destination) is searched as the optimum route, and some selected routes are selected as candidate routes in the order of the link cost. The candidate routes searched here are each expressed as a string of links shown in FIG.

FIG. 5 shows an example of the data structure of the candidate route searched by the route search unit 112.
(A) shows, as an example, the data structure of route data 50 searched under a route search condition with priority on time required, and (B) and (C) show road shape data of each link included in route data 50. The data structure of 51 and the name data 52 is shown.

  The route data 50 is composed of a plurality of data blocks corresponding to the candidate route, and each data block includes a plurality of ((time required) arrival times (or required times) 501 when the route is used and a plurality of ( n links) are represented by a pair of link ID: 502-i and link length 503-i (i = 1 to n).

  The road shape data 51 is a data block generated in correspondence with the link ID 502 indicated by the route data 50. For example, the link ID 511, the start / end position 512, the time required for passing the link 513, and the congestion degree 514 The link start point ID 515, the end node ID 516, the number of coordinate points (n) 517 specifying the link shape, and the n coordinate points 518 (X coordinate 518X-i, Y coordinate 518Y-i). , I = 1 to n). The start / end position 512 indicates a coordinate value representing the position when the current position or destination is in the middle of the link. Further, the values of the required time 513 and the congestion degree 514 are extracted from the traffic information data distributed from the traffic information distribution server 30.

  The name data 52 is also a data block generated corresponding to the link ID 502 indicated by the route data 50. For example, the link ID 521, the number of intersection names (k) 522 existing in the link, and the intersection name 523 ( 523-1 to 523-k), the number of road names (m) 524 of the links, and individual road names 525 (5255-1 to 525-m). When one link is a part of the national highway y line and a part of the xx road, the name data 52 has two road names 525.

FIG. 6 is a flowchart showing the function of the route schematic diagram generation unit 113.
The route schematic diagram generation process 113 analyzes the connection relationship between candidate routes based on the plurality of candidate route data 50 generated by the route search unit 112, and generates simplified route data suitable for the summary map. Relationship analysis processing (step S1) and detour integration processing for integrating a plurality of detours into one link by omitting the connection relationship of the detour portions with low importance from the simplified route data constructed in step S1 (Step S2), a summary map generation process (Step S3) for generating a summary map based on route data further simplified by omitting the connection relationship, and traffic information is added to each route on the summary map. Traffic information addition processing (step S4), character information addition processing for adding road names to each route (step S5), and display processing for outputting a summary map having traffic information and road names to the display unit 105 Consisting of a (step S6).

  In step S1, a section in which a plurality of routes overlap each other, that is, a basic link sequence connected to a branch point or junction of the routes is extracted from the candidate route data generated by the route search unit 112, and the basics of the overlapping sections are extracted. Simplified route data is generated by combining the link strings into one, combining the basic link strings of the non-overlapping sections into one, and assigning a new link identifier to each section. In the simplified route data, by defining a branch point or a junction point between candidate routes as a node, a data structure in which nodes are connected by a link extended in terms of distance from the link unit indicated by the original route data 50, and Become.

  For example, it is assumed that the candidate routes R1, R2, and R3 searched by the route search unit 112 are in the connection relationship shown in FIG. 7, and each route data includes the basic link sequence shown in FIG. Here, the node S indicates the departure place, the node G indicates the destination, and a01 to a20 indicate the original link identifiers (basic link identifiers) used in the map data.

  The route R1 is the optimum route and is composed of links a01 to a10. The routes R2 and R3 are inferior to the optimal route R1 in terms of cost, the route R2 is composed of links a01, a02, a11 to a16, a09, and a10, and the route R3 includes links a01, a02, a11, It is comprised from a12, a17-a20, a09, and a10.

  As indicated by an arrow 1 between the route data, routes R1, R2, and R3 overlap in a section between links a01 and a02 and links a09 and a10, and paths R2 and R3 overlap in a section between links a11 and a12. ing. In the route connection relation analysis process (step S1), these overlapping sections are extracted from the route data of R1, R2, and R3, and new link identifiers (extended link identifiers) L1 to L6 are assigned to the overlapping sections and the non-overlapping sections. Thus, simplified route data is generated.

FIG. 9 shows the relationship between the nodes and links included in the simplified route data generated in the route connection relationship analysis process (step S1), and the routes R1 to R3. FIG. 10 shows the simplified routes of the routes R1 to R3. The data structure is shown.
Here, the arrow 2 represents a link overlapping between routes, and the symbols N1 to N5 represent nodes in the simplified route data. The node N1 is the departure point S, the node N4 is the destination G, the end point node N2 of the link L1 is the branch point of the route R1 and the other two routes, the end point node N5 of the link L4 is the branch point of the routes R2 and R3, and the link In the start point node N3 of L3, the paths R1, R2, and R3 are junctions.

  In the simplified route data, each route is defined by the extended link identifier column (L1, L2,...) Shown in FIG. 10, but each extended link identifier is as shown in FIG. Are associated with one or more basic link identifiers. Therefore, if the extended link identifier is designated, the basic link identifier is specified, and the road shape data 51 and the name data 52 shown in FIG. 5 can be accessed.

  A summary map showing a plurality of candidate routes displayed for selecting an initial route can be generated using the simplified route data. However, in the simplified route data generated in step S1, if the number of route branch points and merge points is large, the route connection relationship on the summary map becomes complicated, and it is difficult for the user to understand the relationship between candidate routes. It will be a thing. Thus, in this embodiment, in step S2, unnecessary connection relationships between paths are omitted from the simplified path data constructed in step S1, and a plurality of detours are integrated. The route connection relationship omission processing (detour integration processing) will be described in detail later. Here, the summary map generation method based on the simplified route data and the number of branch points and merge points are large. The problem of will be described.

  FIGS. 11A to 11D show an example of a summary map generation process generated in the summary map generation process (step S3) based on the simplified route data. Here, the simplified route data of routes R1 to R3 shown in FIG. 10 is used. It is assumed that the route priority is in the order of R1, R2, and R3.

  In this embodiment, the summary map is drawn on equally spaced grid lines. In the first step S100, the departure node N1 (= S) is arranged on the lower side, the destination node N4 (= G) is arranged on the upper side, and the node N2 of the highest priority route R1 is placed on the straight line connecting the nodes N1 and N4. N3 are arranged at equal intervals, and links L1, L2, and L3 are arranged.

  In the next step S101, the links L4 and L5 on the route R2 are arranged as a detour for the link L2 connecting the nodes N2 and N3, and the node N5 connecting the links L4 and L5 is generated between the nodes N2 and N3. On the horizontal grid. Whether the link L4 is detoured to the left or right of the branch node N2 is determined by the actual positional relationship between the links L2 and L4 at the node N2.

  The positional relationship between the links L2 and L4 is associated with the sequence of coordinate points of the road shape data 51 associated with the first basic link a03 constituting the link L2 shown in FIG. 8 and the first basic link a11 constituting the link L4. This is determined by comparison with a sequence of coordinate points of the road shape data 51 to be performed. Therefore, for example, the angle θ between the arranged link L2 and the new link L4 is calculated with the counterclockwise angle being positive, and if θ> 0, the left turn is determined, and if θ <0, the right turn is determined. What is necessary is just to determine a detour direction.

  In the next step S102, a link L6 on the route R3 is arranged as a detour for the link L5 connecting the nodes N5 and N3. Whether the link L6 is diverted to the left or right of the branch node N5 is determined by the actual positional relationship between the links L5 and L6 at the node N5. Since the detour of the link L5 consists only of the link L6 and there is no node on the way, the link L6 is provided along the left side of the node N5 or along the vertical grid line newly generated between the nodes N5 and N3. Step S102 is completed. If this detour has a plurality of links and there are nodes to be arranged on the detour, the nodes are arranged at equal intervals on the detour. In the present embodiment, the arrangement of all the routes in the summary map is completed by executing step S102.

  Finally, in step S103, after adjusting the vertical and horizontal axes of the detour part so that all the grid lines are equally spaced, the detour is made within the range where the routes do not overlap with each other according to the screen size. Compress horizontally. In FIG. 11, finally, the vertical interval of the grid lines is dy, and the horizontal interval is dx. The final summary map may include other node indications indicating, for example, interchanges in addition to the branch points and junctions of the route.

FIG. 12 shows a map (A) based on the actual road shape of the routes R1 to R3 and a summary map (B) generated by the summary map generation process (step S3) described above.
In the map display based on the actual road shape, for example, in places where nodes are close to each other such as N1 and N2, N2 and N5, and N3 and N4 in FIG. Therefore, it becomes difficult to correctly convey the explanation information of the candidate route to the user. On the other hand, when the summary map display places importance on the connection relationship between candidate routes as shown in FIG. 12B, sufficient space is secured between nodes for displaying traffic information and displaying character strings such as road names. Therefore, it is possible to correctly convey the explanation information of the candidate route to the user.

FIG. 13 shows an example of a display screen of a route schematic created based on the above-described summary map.
In the route schematic diagram shown on the display screen, as indicated by reference numeral 3, on the summary map generated in step S3, traffic information representing a congested section, a congested section, etc. is superimposed in step S4, and in step S5, The content is superimposed with character information indicating a road name. Reference numeral 4 denotes a cost information display area indicating a required time, a travel distance, a fee, and the like for each candidate route.

  In the illustrated example, only the traffic jam information is displayed as the traffic information. However, for example, traffic regulation and other events may be displayed as icons. In addition, various display forms such as a paint pattern and a color-coded display can be applied to distinguish between a congestion section and a congestion section.

  FIG. 13 is a schematic diagram showing a plurality of candidate routes on the display screen for selecting an initial route. However, during route guidance along the initial route selected by the user, When this occurs, the connection relationship of the route ahead from the branch point may be displayed in a route schematic diagram as shown in FIG. 13 to give the user an opportunity to change the route.

Next, detour integration processing in a route having a large number of branch points and junctions will be described.
14A shows an example of a map based on the actual road shape of the routes R1 to R3, and FIG. 14B shows a summary map of the routes R1 to R3 before the detour integration. The route diagram of FIG. 14 has a pattern in which two routes R2 and R3 frequently repeat branching and merging, such as nodes N5-N6, N7-N8, and N9-N10.

  FIG. 15A shows another example of a map based on the actual road shape of the routes R1 to R3, and FIG. 15B shows a summary map of the routes R1 to R3 before detour integration. The route diagram of FIG. 15 has a pattern in which branching and merging are frequently repeated in the vicinity of the starting point and the destination, such as nodes N2-N3, N4-N5, and N8-N9.

  In these route patterns, as can be seen from FIG. 14B and FIG. 15B, even when the candidate route is displayed as a summary map, the branching and merging of the route are repeated, and the display content is difficult for the user to see. . In addition, when the nodes are displayed at equal intervals, the route size between the departure node and the destination node is enlarged, so if the vertical grid size of the summary map is reduced to match the screen size, traffic congestion will occur. There is a problem that there is a shortage of display space for information and road names.

  In the alternative route integration process (S2) shown in FIG. 6, in the route diagram having a large number of branch points and merging points as described above, the connection relationship of the alternative route portion that is not important for the route selection by the user is selectively omitted. In order to further simplify the summary map.

  FIG. 16 is a flowchart illustrating an example of a processing procedure performed in the detour integration processing (S2). In the present embodiment, the route connection relationship is simplified by integrating links of relatively short distances that are in an alternative relationship with each other.

  In the detour integration processing (S2), the processor 101 first sets the value of the parameter i for selecting one of a plurality of candidate routes to an initial value “1” (step S200), and sets the route Ri It is determined whether route data exists (S201). If the route data for the route Ri does not exist, the processor 101 determines that the detour integration processing for all candidate routes has been completed, and the processor 101 ends this routine.

  On the screen for selecting a route from the starting point to the destination, links that merge immediately after branching are considered to be less valuable to be displayed on the screen as alternative routes. Therefore, when route data of the route Ri exists, the processor 101 compares the number N of nodes included in the route Ri with a threshold Th (S202). The number N of nodes includes a departure node and a destination node in addition to a branch point node and a junction node on the route Ri. If the number N of nodes is equal to or less than the threshold Th, the processor 101 determines that it is not necessary to omit the connection relationship in the path Ri, increments the value of the parameter i (S206), and returns to step S201.

  When the number of nodes N exceeds the threshold Th, the processor 101 determines whether or not a link that can be integrated with another route exists in the route Ri (S203). The value of i is incremented (S206), and the process returns to step S201. Here, the link that can be integrated means a set of links (alternative links) in which the start node and the end nodes coincide with each other.

  In the route diagram illustrated in FIG. 14, two links L5 and L11 that connect nodes N5 and N6, two links L7 and L12 that connect nodes N7 and N8, and two links L9 and L13 that connect nodes N9 and N10, Each becomes a link that can be integrated. In the route diagram illustrated in FIG. 15, three links connecting the nodes N2 and N3, three links connecting the nodes N4 and N5, and three links connecting the nodes N8 and N9 are integration links.

  If there is a link that can be integrated in the route Ri, the processor 101 integrates alternative links that satisfy a predetermined integration condition among the links that can be integrated into one link (S204). For example, if the threshold distance Lmin is specified as the link integration condition, and there is a straight line distance from the start point node to the end point node or a link whose link length is shorter than the threshold distance among the alternative links, these alternative links are selected. Merge into one link. However, alternative links that have already been integrated by the link integration processing in other routes are excluded from the integration targets.

  Link integration is a group of links that have a low display importance (high integration priority) among a plurality of integrable links that satisfy the link integration condition, in other words, those that have a high margin for the threshold indicated by the link integration condition. It carries out in order from. When the number of nodes is equal to or less than the threshold value, or when there is no link that can be integrated on the route Ri, the processor 101 ends the link integration processing (S204) on the route Ri, and is connected and expanded by link integration. Is assigned a new link identifier (S205), the value of parameter i is incremented (S206), and the process returns to step S201.

  As described with reference to FIG. 8, the simplified route data handled in the link integration process (S204) is obtained by replacing each candidate route defined by the basic link identifier column (a01, a02,...) Of the map data between routes. Each route Ri is represented by a sequence of extended link identifiers (L1, L4,...) Divided into a plurality of sections (overlapping sections and non-overlapping sections) based on the connection relationship and assigned to each section. . In the link integration process (S204), when a plurality of sets of alternative links satisfying the link integration condition are found, the links are integrated in order from the alternative link group having the highest integration priority. The link integration here means that, for example, an integration mark is given to each integrated link (link identifier Li). The integration mark may include information indicating the integration priority.

  When the detour links are integrated, the route overlap section that has been divided before and after the detour section changes to a continuous route overlap section through the integration section. In step S205, a new link identifier Lx is assigned to the route overlap section unified by link integration in this way. If the basic link identifiers a01, a02,... Are the first layer identifiers, and the extended link identifiers L1, L2,. The identifiers Lx1, Lx2,... Are the third layer identifiers.

  FIG. 17B shows a summary map obtained when the value of the node threshold Tmin is set to “5” and the detour integration processing (S2) is performed on the route diagram of FIG. By the detour integration processing, the detour portions indicated by reference numerals 40 to 42 in FIG. 17A are each integrated into one link, and as indicated by reference numeral 43 in FIG. A summary map in which all the links of the route R3 are integrated into the route R2 is obtained at the detour L20 between the two. If the value of the node threshold Tmin is set to “4”, the two links L5 and L11 between the nodes N5 and N6 having the lowest integration priority are excluded from the integration targets. Accordingly, as a result, a summary map is obtained in which the alternative link between the nodes N5 and N6 shown in FIG.

  In the routes R1 and R2 illustrated in FIG. 17A, the integration processing is executed in the order of the detour portions 41, 42, and 40 in the order of the shortest alternative link distance, and the integration priority “1” is assigned to the links L7 and L12. The links L9 and L13 are marked with the integration priority “2”, and the links L5 and L11 are marked with the integration priority “3”.

  FIG. 18B shows a summary map obtained when the value of the node threshold Tmin is set to “5” and the detour integration processing (S2) is performed on the route diagram of FIG. In this case, the detour portions indicated by reference numerals 50 to 52 in FIG. 18A are integrated, and as indicated by reference numerals 53 and 54 in FIG. 18B, between the nodes N1 and N6 and the nodes N7 and N9. A summary map in which all the links of the routes R1 to R3 are integrated is obtained.

  According to the above-described embodiment, it is possible to simplify the summary map by omitting the connection relation between the routes in the detour portion having a low display value as an alternative route, thereby securing a display space such as traffic jam information and road names. It is possible to provide route information that can be easily understood by the user with a route schematic diagram. However, by partially omitting the connection relationship, the user cannot confirm all of the connection relationships of the candidate routes at the branch point and the merge point on the route schematic diagram display screen.

  Therefore, as still another embodiment of the present invention, a navigation device that can easily check the branching and merging state of the route portion omitted in the route schematic diagram (summary map) by changing the display screen will be described. To do.

  FIGS. 19A to 19D show transition of the display screen of the route schematic diagram corresponding to the route of FIG. The route schematic diagram initially presented on the display screen shows the summary map of FIG. 17 (B) in which the detour links are integrated, as shown in FIG. 19 (A). In the present embodiment, by enclosing a partial area on the summary map with a broken line 60, the user is shown to be hiding the detour route omitted in link integration.

  To determine whether each link on the summary map is a link integrated, it is only necessary to determine whether it is a link having a third layer link identifier Lx. As described above, in the summary map shown in FIG. 19A, the link identifier Lx1 of the third layer is assigned only to the link L20. Therefore, the broken line area 60 is displayed so as to surround the link L20.

  When the user selects the broken line area 60 by, for example, a cursor operation or the like, the summary map screen is displayed that reproduces the hidden detour in the order of lower integration priority (in the order of higher display importance). On the first transition screen (B), the broken line area 60 is enlarged to display a summary map in which nodes N5 and N6 having the lowest integration priority and a detour between them are added. If the detour route omitted in link integration is also hidden in this summary map, a new broken line area 61 is displayed. In this example, a broken line area 61 is displayed in the link portion corresponding to the sections indicated by reference numerals 41 and 42 in FIG. In the transition screen, since the partial area of the summary map showing the reproduced detour is enlarged and displayed, the display content can be moved according to the scroll operation.

  When the user selects the broken line area 61, the display screen changes to FIG. (C), the broken line area 61 is enlarged, and nodes N9 and N10 having the next lowest integration priority and a detour between them are added. A summary path showing a new broken line area 62 is displayed. In this example, a broken line area 62 is displayed at the link portion corresponding to the section indicated by reference numeral 42 in FIG. When the user further selects the broken line area 62, the display screen transitions to FIG. (D), the broken line area 612 is enlarged, and nodes N9 and N10 having the highest integration priority and a detour between them are added. The route is displayed.

  The above-described display screen transition function can be provided as an optional function in the route schematic diagram generation unit 113. For example, in the flowchart of the route schematic diagram generation unit shown in FIG. 6, after the screen display process (S6), a display transition control unit is added, and the user selects a link integration region by a cursor operation on the display screen. When the display transition control unit generates simplified route data in which the set of alternative links with the integration mark is returned to the state before the integration, and passes this to the summary map generation processing unit S3 Good.

  20A to 20D show the transition of the display screen of the route schematic diagram corresponding to the route of FIG. The route schematic diagram initially presented on the display screen shows the summary map of FIG. 18B in which the detour links are integrated as shown in FIG. In the case of the present embodiment, since the link integration points are divided into the departure point node side and the destination node side, two broken line areas 70 and 71 indicating the positions of the hidden detours are displayed.

  When the user selects the broken line area 70 by a mouse operation or the like, the display screen changes to FIG. (B), the broken line area 70 is enlarged, and a summary path in which nodes N8 and N9 and a detour between them are added is displayed. Is displayed. When the user selects the broken line area 71 on the screen of FIG. (A), the display screen transitions to FIG. (C), expands the broken line area 71, and displays the nodes N2 and N3 and the detour between them. In addition, a summary path showing a new broken line area 72 is displayed. When the user selects the broken line area 72, the display screen transitions to FIG. (D), and the broken line area 612 is enlarged, and the summary path to which nodes N4 and N15 and a detour between them are added is displayed.

  19 and 20, only the summary map portion is shown, but the route schematic diagram actually provided to the user has traffic information and text information superimposed on these summary maps as described in FIG. It will be a thing.

Next, a description will be given of an embodiment in which the above-described route schematic diagram of the present invention is provided to a navigation device by a Web service.
FIG. 21 shows the traffic information distribution server 30 accessed from the navigation device 10 shown in FIG. The traffic information distribution server 30 of the present embodiment has a high-precision traffic jam prediction function, and provides traffic information and route schematic map information providing service in response to requests from the navigation devices 10.

  In the navigation device 10 of the present embodiment, when the user designates a destination from the input unit 104, the route guidance control unit 111 acquires the position information of the current location (departure location) acquired by the current location acquisition unit 103, the destination, Then, a route schematic map request message indicating the route search condition is transmitted to the traffic information distribution server 30, and a response message including route schematic map information from the departure point to the destination is received from the traffic information distribution server 30. In the route schematic map request message, the destination is specified by the destination name input by the user or the position information (coordinate value) converted from the destination name.

  In this embodiment, since the route schematic diagram can be obtained from the traffic information distribution server 30, the navigation device 10 does not require the route schematic diagram generation unit 113 shown in FIG. A route schematic diagram extracted from the response message from the traffic information distribution server 30 by the route guidance control unit 111 is displayed on the display unit 105. In order to display the route schematic received from the traffic information distribution server 30, a route schematic processing unit that receives a response message from the route guidance control unit 111, extracts the route schematic from the response message, and outputs the route schematic to the display unit 105. The memory 107 may be provided.

  The traffic information distribution server 30 includes a processor 300, a map data storage unit 301 for storing map data, a traffic information storage unit 302 for receiving and storing traffic information from the traffic control system, and a line interface connected to the network NW. 303 and a memory 304. The memory 304 includes, as software related to the present invention executed by the processor 300, a request response unit 310, a traffic information search unit 311, a route search unit 312 that performs a route search in consideration of traffic information, and the navigation device 10. And a route schematic diagram generation unit 313 that generates a route schematic diagram in response to a request from the user.

  The request message transmitted from the navigation device 10 is received by the request response unit 311. The request response unit 311 executes the traffic information search unit 311 when the received message is a traffic information request message, and executes the route search unit 312 when the received message is a route schematic diagram request message.

  When the route search unit 312 selects a plurality of candidate routes from the departure point to the destination according to the route schematic map request message, the route schematic map generation unit 313 performs the procedure described in FIG. Generate an abbreviated route schematic. The route schematic diagram generated by the route schematic diagram generation unit 313 and the traffic information searched by the traffic information search unit 311 are edited into a response message by the request response unit 311 and transmitted to the requesting navigation device 10 respectively. .

  In addition to the candidate route searched by the route search unit 312, the candidate route searched by the route search unit 112 on the navigation device 10 side can be used for the generation of the route schematic diagram on the traffic information distribution server 30 side. Good. In this case, the route information searched on the navigation device 10 side is notified to the traffic information distribution server 30 by a route schematic diagram request message.

  When the road data stored in the map data storage unit 102 on the navigation device 10 side and the road data stored in the map data storage unit 301 on the traffic information distribution server 30 side are managed with a common link ID, Candidate routes searched by the route search unit 112 can be notified to the traffic information distribution server 30 in the form of a link ID string. If the road data is managed by different link IDs, the candidate route searched by the route search unit 112 is notified to the traffic information distribution server 30 in the form of a coordinate sequence, and coordinate sequence matching is performed on the traffic information distribution server 30 side. Thus, the identification of the link and the connection relationship between the links are determined.

FIG. 22 shows a configuration example of the traffic information distribution server 30 suitable for distributing a route schematic diagram to a simple navigation system called PND (Personal Navigation Device).
As illustrated, the traffic information distribution server 30 of the present embodiment includes a route search condition setting unit 314 and route search conditions 315 (315-1 to 315-n) in addition to the components described in FIG. It has a configuration.

  The navigation apparatus 10 applied to the present embodiment omits the map data storage unit 102, the route search unit 112, the route schematic diagram generation unit 113, and the route search condition setting unit 114 from the configuration shown in FIG. In addition, the input reception control unit 110 and the route guidance control unit 111 are provided.

  When the user designates a destination from the input unit 104, the route guidance control unit 111 transmits a route schematic map request message indicating the current location (departure location) location information acquired by the current location acquisition unit 103 and the destination. It transmits to the information distribution server 30 and receives from the traffic information distribution server 30 a response message including route schematic map information from the departure point to the destination.

  The route schematic diagram received from the traffic information distribution server 30 is output to the display unit 105 by the route guidance control unit 111. However, as described with reference to FIG. 21, a route schematic diagram processing unit that receives a response message from the route guidance control unit 111, extracts a route schematic diagram from the response message, and outputs the route schematic diagram to the display unit 105 may be provided in the memory 107. .

  The traffic information distribution server 30 extracts the location information and the destination of the departure place from the route schematic map request message received from the navigation device 10, converts the destination into the location information, and then the route search unit 312 starts from the departure place. Search for multiple candidate routes to the destination. In this case, as a route search condition, for example, time priority is specified as a default condition. The route schematic diagram generation unit 313 generates a route schematic diagram in the same procedure as in FIG. 6 based on the candidate route searched by the route search unit 312. The generated route schematic diagram is edited into a response message by the request response unit 311 and is transmitted to the requesting navigation apparatus 10.

The figure which shows one Example of the navigation system to which this invention is applied. The figure which shows the structural example of the map database 40 for navigation stored in the map data storage part. The figure which shows the hierarchical structure of the map data stored in the map data storage part. The figure which showed an example of the basic composition of the road data 401. FIG. The figure which shows an example of the data structure of the candidate path | route searched with the path | route search part. The flowchart which shows the function of the route schematic map production | generation part 113. FIG. The figure which shows one example of candidate path | route R1, R2, R3 searched in the route search part 112. FIG. The figure which shows the link row | line | column of candidate path | route R1, R2, R3 shown in FIG. The figure which shows the relationship between the node and link contained in the simplified path | route data produced | generated by path | route connection relationship analysis processing (step S1), and path | route R1-R3. The figure which shows the structure of the simplified path | route data of path | route R1-R3 shown in FIG. The figure which shows an example of the production | generation process of the summary map produced | generated by the summary map production | generation process (step S3) based on the simplified path | route data. The figure which shows the map (A) based on the actual road shape of path | route R1-R3, and the summary map (B) produced | generated by the summary map production | generation process (step S3) mentioned above. The figure which shows an example of the display screen of the route schematic created based on the summary map. The figure which shows the other example (A) of the route map based on an actual road shape, and the summary map (B) before omitting a connection relationship. The figure which shows further another example (A) of the route map based on an actual road shape, and the summary map (B) before omitting a connection relationship. The flowchart which shows an example of the omission procedure of the route connection relationship by a detour integration process (S2). The figure which shows the omission location (A) of the path | route connection relationship at the time of performing a detour integration process (S2) to the path | route shown to FIG. 14 (A), and the summary map (B) obtained. The figure which shows the omission location (A) of the path | route connection relationship at the time of performing a detour integration process (S2) to the path | route shown to FIG. 15 (A), and the obtained summary map (B). The figure which shows the transition of a display screen in the case of reproducing an omission location from the route schematic of FIG. The figure which shows the transition of a display screen in the case of reproducing an omission location from the route schematic of FIG.18 (B). The figure which shows one Example of the traffic information delivery server 30 provided with the provision service function of route schematic map information. The figure which shows the other Example of the traffic information delivery server 30 provided with the provision service function of route schematic map information.

Explanation of symbols

10: Navigation device, 20: Base station, 30: Traffic information distribution server, 40: Map database, 50: Route data, 51: Road shape data, 52: Name data,
100: control unit, 101: processor, 102: map data storage unit, 103: current position acquisition unit, 104: input unit, 105: display unit, 106: communication unit, 107: memory, 110: input reception control unit, 111 : Route guidance control unit, 112: route search unit, 113: route schematic map generation unit, 114: route search condition setting unit, 115: route search condition,
300: Processor, 301: Map data storage unit, 302: Traffic information storage unit, 303: Line interface, 304: Memory, 310: Request response unit, 311: Traffic information search unit, 312: Route search unit, 313: Route outline Figure generation unit, 314: route search condition setting unit,
S1: Route connection relation analysis processing, S2: Detour integration processing, S3: Summary map generation processing, S4: Traffic information addition processing, S5: Name information addition processing, S6: Display processing.

Claims (16)

A navigation device for displaying a plurality of routes from a departure place to a destination as a schematic diagram on a display screen,
A route search unit for searching a plurality of routes from the map data to the destination,
A route schematic map generation unit that generates a route schematic map based on the route data indicating the plurality of searched routes,
The route schematic diagram generation unit
Analyzing the route data, dividing each route into a section that overlaps with any other route and a bypass section that does not overlap with other routes, and according to a predetermined link integration condition, The section is changed to a route overlap section, and the optimum route of the plurality of routes is represented by a first straight line having one end as a start node and the other end as an end node, and the detour sections of the remaining routes in order of priority And the second straight line arranged in parallel with the first straight line, and both ends of the second straight line on the first straight line, Alternatively, a summary map in a form combined with a branch point node or a junction node provided on the second straight line indicating another route that has been arranged is generated, and name information and traffic state information are given to the summary map, Output to the display unit as the above route schematic diagram. Ke - Deployment apparatus. The route schematic diagram generating unit
From the route data, each route is represented by a new link identifier column assigned to each overlap section and each detour section, and according to the integration condition, some detour sections are changed to overlap sections. , Generate simplified route data with the link junction from the overlap section and the link junction of the detour section as the branch node and junction node,
The navigation device according to claim 1, wherein the summary map is generated based on the simplified route data.   The route schematic diagram generation unit generates a summary map in which each of the branch point nodes and the merging point node is located at the intersection of the vertical grid line and the horizontal grid line regardless of the actual distance from the start point node. The navigation device according to claim 1.   The route schematic diagram generation unit determines a branch direction of the second straight line according to position information of each route at the branch point node or the junction node indicated by the map data. Navigation device. A wireless communication unit for communicating with a traffic information distribution server via a network;
The route search unit acquires the traffic state information of each route from the traffic information distribution server, generates route data having traffic state information for each basic link indicated by the map data,
2. The navigation apparatus according to claim 1, wherein the route schematic diagram generation unit adds traffic state information to the summary map using traffic state information indicated by the route data. A navigation device that displays a plurality of routes from a departure point to a destination as a schematic diagram on a display screen,
A route search unit for searching a plurality of routes from the map data to the destination,
A route schematic diagram generating unit that generates a route schematic diagram based on the route data indicating the plurality of searched routes,
The route schematic diagram generation unit
Analyzing the route data, dividing each route into a section that overlaps with any other route and a detour section that does not overlap with other routes, and each route is divided into overlapping sections and detour sections A route connection relation analysis processing unit for generating route data expressed by a column of extended link identifiers assigned to
A detour integration process for detecting a detour section satisfying a predetermined link integration condition based on the path data generated by the path connection relation analysis processing unit, and integrating a plurality of links in the detour section into one link And
Based on route data whose route connection relationship has been further simplified by integration of the detour, the optimum route of the plurality of routes is represented by a straight line having one end as a start node and the other end as an end node. A summary map generation processing unit that generates a summary map in a form in which a route is represented by a broken line and both ends of each broken line are connected to a branch point or a merge point on another route;
A traffic information addition processing unit for superimposing traffic state information on the summary map;
A navigation apparatus comprising: a character information addition processing unit that superimposes character information including a road name on the summary map.   7. The detour integration processing unit integrates a plurality of links in a detour section satisfying the link integration condition into one link in a route in which the number of nodes exceeds a predetermined threshold value. The navigation device described in 1.   In order from the detour section with the lowest display importance, the detour integration processing unit performs the multi-link integration process until there is no detour section satisfying the link integration condition or the number of nodes decreases to the threshold value or less. The navigation device according to claim 7, wherein the navigation device is repeated.   8. The navigation device according to claim 7, wherein the route schematic diagram generation unit includes means for selectively reproducing a detour section hidden by link integration in response to a user operation. A navigation system comprising a traffic information distribution server connected to a network and a navigation device that communicates with the traffic information distribution server via the network,
The traffic information distribution server includes a map data storage unit, a traffic information storage unit, a route search unit, a route schematic diagram generation unit, and a request response unit.
The navigation device transmits a route schematic map request message specifying a departure point and a destination to the traffic information distribution server, and outputs a route schematic map acquired from the traffic information distribution server to a display screen. Prepared,
The route search unit of the traffic information distribution server searches for a plurality of routes from the map data to the destination according to the route schematic map request message,
Based on the route data obtained from the route search unit, the route schematic diagram generation unit integrates a plurality of links in a detour section satisfying a predetermined link integration condition into one link, and then among the plurality of routes The optimal path is represented by a straight line with one end as the start node and the other end as the end node, the remaining paths are represented by broken lines, and both ends of each broken line are connected to branch points or merge points on other paths. Generate a summary map,
The navigation system, wherein the request response unit transmits a response message including the summary map to the navigation device.   The route schematic diagram generation unit analyzes the route data obtained from the route search unit, and the route is overlapped with any other route, and the route is not overlapped with another route. Dividing, by changing the specific detour section to the route overlap section by the link integration, expressing the optimum route of the plurality of routes as a first straight line having one end as a start node and the other end as an end node, In order of priority, a path portion composed of a detour section of the remaining path and an overlapping section with another remaining path is expressed by a second straight line arranged in parallel with the first straight line, and the second The summary map is generated by coupling both ends of a straight line to a branching node or a junction node provided on the first straight line or a second straight line indicating another route that has been arranged. The navigation system according to claim 9. . The route schematic diagram generating unit
From the route data, each route is represented by a new sequence of link identifiers assigned to each overlap section and each detour section, and the link branch point from the overlap section and the link merge point of the detour section are branched. 11. The navigation system according to claim 10, wherein route data is generated as a point node and a merging point node, and the summary map is generated based on route data further simplified by the link integration. .   The route schematic diagram generation unit generates a summary map in which each of the branch point nodes and the merging point node is located at the intersection of the vertical grid line and the horizontal grid line regardless of the actual distance from the start point node. The navigation system according to claim 10. A route display method for displaying a plurality of routes from a starting point to a destination as a route schematic on a screen,
Searching for multiple routes from the map data to the destination;
Generating a route schematic based on the route data indicating the searched plurality of routes;
And output the above route schematic on the screen.
In the above route schematic generation step,
Analyzing the route data, dividing each route into a section that overlaps with any other route and a detour section that does not overlap with other routes,
Change the detour section satisfying the predetermined link integration condition to the route overlap section,
Of the above multiple routes, the optimal route is represented by a straight line with one end as a start node and the other end as an end node, the remaining routes are represented by broken lines, and both ends of each broken line are branched or merged on other routes. Generate a summary map in the form of points
A route display method characterized in that name information and traffic state information are given on the summary map to obtain the route schematic diagram. In the step of generating the route schematic diagram, the optimum route is represented by a first straight line, and a route portion including a detour section of the remaining route and an overlapping section with another remaining route is arranged in the order of priority. A branch point expressed by a second straight line arranged in parallel with the straight line, and both ends of the second straight line provided on the first straight line or on a second straight line indicating another route already arranged The route display method according to claim 13, wherein the summary map is generated by coupling to a node or a junction node. In the step of generating the route schematic diagram,
From the route data, each route is represented by a new sequence of link identifiers assigned to each overlap section and each detour section, and the link branch point from the overlap section and the link merge point of the detour section are branched. 14. The route display method according to claim 13, wherein route data for generating a point node and a merging point node is generated, the route data is further simplified by changing the section, and the summary map is generated.

Images