JP2003194560A - Route search apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a technique by which a route is searched according to a regulation on a passage method. <P>SOLUTION: In a node A, a node B, a node C and a node D which are connected by links at costs, under a four-point regulation which inhibits an advance to a node E succeeding to a route A to a route B to a route C; a route up to the destination node E from the starting-point node A is searched. The route search apparatus searches the route while label data is being created according to a tip node in a candidate route. In addition to a cost value up to the node, nodes in two points immediately before the tip node are recorded in the label data, a plurality of label data in which parts in the two nodes immediately before the tip node are different are recorded so as to correspond to one node, and the route based on the cost value can be searched so as to correspond to the four-point regulation. <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 technique for conducting a route search according to restrictions on passing methods.

[0002]

2. Description of the Related Art In recent years, the field of use of route search devices has become extremely widespread. For example, many so-called car navigation systems have a route search function. The car driver can search for a desired route by setting the current position and the destination.

The route search is often performed by the Dijkstra method. The Dijkstra method is a method of expressing a traffic route with a set of nodes and links, assigning a cost according to the traffic distance to each link, etc., and searching for a route that minimizes the total cost from the starting point to the destination. Say.

[0004]

However, in the Dijkstra method, when the passing method is restricted, it is not possible to carry out an appropriate route search.

FIG. 1 is an explanatory view showing an example of a passage in which the passage method is restricted. In FIG. 1, the nodes A, B, C and D are connected by a link. Here each link has a positive integer cost value. For example, node B is node A
And C are linked by a link. The link connecting to node A has a cost of 3, and the link connecting to node C has a cost of 2. Further, although the node B does not have a link connecting to the node D, the link B has the node C as a relay point.
There is a path composed of C and CD. The cost of the route is given by the total cost of the links included therein, and the cost of the route B → C → D is 4.

Here, it is assumed that the user desires to search for a route from the departure node A to the destination node D.

In the Dijkstra method, a search is performed while following a link for a candidate route having a starting node or the like as one end point. At this time, the total cost from the departure node to the node is recorded as label data for each node. The extension of the candidate route to a certain node is performed only when the cost stored in the label data of the node can be improved. That is, when a new candidate route extending to a node in which label data is already stored appears, a route is selected according to the size relationship between the total cost of the candidate route and the cost value stored in the label data. When the total cost of the new route is smaller, the label data is rewritten. By repeating such a procedure, it is possible to search for a route that reaches the destination node at the minimum cost.

However, such a conventional route search technique cannot deal with the case where there are restrictions on the passage method of nodes and links. In FIG. 1, as an example of the regulation, there is a right turn prohibition regulation when traveling from the node A to the node C. In other words, it is a regulation that prohibits the route “A → C → D”. The abstract structure composed of nodes, links, and costs as illustrated in FIG. 1 will be referred to as a graph below.

In this example, when the conventional route search device finds a route with a cost of 1 from the departure node A to the intermediate node C, the other candidate routes have a cost of greater than 1 and thus reach the node C. There was no room to choose as. That is, “A → B → C” and “A → C → B →
The candidate route with the cost 5 following "C" was excluded by the cost comparison with the candidate route "A → C" with the cost 1. On the other hand, the route “A → C → D” cannot be selected because it violates the regulation. As a result, "A->B->C->D" and "A->C->B->C->D" as routes that do not violate regulations.
However, the desired route search result could not be obtained.

As one of methods for solving the above problems, for example, a technique described in Japanese Patent Laid-Open No. 7-294267 has been proposed. This technique defines each link as a directed link that has a direction as well as connecting nodes, and each link is labeled at the time of route search. The label also includes information designating the link immediately before the link. In this way, it is said that the route search can be realized even if there is traffic regulation by including a label for each link while including the information designating the immediately preceding link. However, with this technology, 4
As for traffic regulation regulated by nodes above the point, it was still impossible to properly search.

Such a problem is not limited to the case described with reference to FIG. 1, but is a problem common to the case of realizing the route search of the passage having the regulation of the passage method.

The present invention has been made in order to solve these problems, and an object of the present invention is to realize a technique for realizing a search for a passage having a regulation of a passage method.

[0013]

Means for Solving the Problems and Their Actions / Effects In order to solve at least a part of the above problems, the present invention adopts the following configuration. A first route search device of the present invention is a route search device that performs a route search, and includes a route data storage unit that stores route data represented by nodes and links as elements, and at least the respective nodes and links. A cost storage unit that stores a cost associated with one side, an instruction input unit that inputs an instruction to select a node corresponding to a departure place and a destination, and a storage content of the passage data storage unit and the cost storage unit. And a route search unit that searches for a route from a starting point to a destination based on the nodes on a plurality of candidate routes, the elapsed nodes from the starting point to the node, and A label information storage unit that generates label information representing an integrated value of costs associated with at least one of the progress links and stores the label information in association with the node; A selection unit that selects one of the candidate routes based on the magnitude relationship of the arithmetic value, the label information storage unit, and a search execution unit that repeatedly uses the selection unit to search for a route to the destination. The label information storage unit can store two or more pieces of label information in association with the node, and when storing two or more pieces of label information, specifies a route in a predetermined section immediately before reaching the node. The point is that the immediately preceding route information is included in each label information and stored.

As described above, according to the present invention, the end points of the candidate routes,
2 to the node or link farthest from the point of departure
It is allowed to store the above label information. That is, the label information is stored at the end points even for the candidate route whose cost is not the minimum. Therefore, there is room for selecting a route by factors other than the cost, and flexible route search can be realized. Examples of factors other than the cost include factors such as traffic restrictions, driver preferences such as giving priority to straight roads, priority to national roads, and the like.

Although the immediately preceding route information specifies the route of the immediately preceding predetermined section, it may be specified by a sequence or set of nodes and links, or a label associated with the immediately preceding node or link. By specifying, the previous route may be recursively specified.

A second route search device of the present invention is a route search device for performing a route search, and a route data storage unit for storing route data represented by nodes and links as elements, and each of the above. A cost storage unit that stores a cost associated with at least one of a node and a link, an instruction input unit that inputs an instruction to select a node corresponding to a departure place and a destination, the passage data storage unit, and the cost storage A route search unit that searches for a route from a starting point to a destination based on the stored contents of the section, and the route searching unit, for nodes on a plurality of candidate routes, from the starting point to the node. Label information storage that generates label information that represents an integrated value of costs associated with at least one of an elapsed node and an elapsed link, and stores the label information in association with the node. Unit, a selection unit that selects one of the candidate routes based on the magnitude relation of the integrated cost value, the label information storage unit, and a search unit that repeatedly uses the selection unit to search for a route to the destination. The label information includes an immediately preceding route information information that specifies label information corresponding to a node immediately before reaching the node.

Label information corresponding to the immediately preceding route is stored in the label information. In the case of multi-point regulation, which is a traffic regulation regulated by four or more nodes, a large number of nodes or links are required to specify the immediately preceding route, resulting in a large amount of data. On the other hand, when it is possible to recursively specify the immediately preceding route by specifying the label information, it is possible to suppress an increase in the data amount even with the multipoint restriction.

Further, flexible label processing can be realized. It is possible to make an inductive change by changing one previous route information.

Here, even when performing a route search that does not allow giving a plurality of label information to one node,
A method of using label information that specifies another label information corresponding to the immediately preceding route is applicable. Also in the second route search device of the present invention, the method of using the label information for specifying another label information corresponding to the immediately preceding route can be applied.

In the route search device of the present invention, at least some of the nodes are provided with a regulation information storage unit that stores regulation information about the passage method, and the selection unit makes the selection in consideration of the regulation information. It may be one.

By doing so, it is possible to realize a flexible route search even if there are restrictions on the passing method.

In the route searching device of the present invention, the regulation information is a regulation defined by N points (N is a natural number of 3 or more) nodes, and the immediately preceding route information corresponds to N-2 points nodes. It may be the route information of the section to be executed.

When the label information for the end points is stored indefinitely, there is a possibility that substantially the same label information is stored in duplicate. As described above, when the regulation information is defined at N points, if the label information having different routes in the section corresponding to the N-2 point node is stored separately, the substantially same label is stored. It is possible to avoid duplication of information.

In the route search device of the present invention, the label information storage unit may suppress generation of label information in which at least a part of the information of the immediately preceding route overlaps.

By doing so, it is possible to suppress the harmful effect caused by creating a large number of pieces of label information having no direct usefulness, and it is possible to reduce the capacity of the label information storage section, for example.

The present invention can be configured in various forms such as a route search device, a computer program for causing a computer to perform a route search, and a route search method using a computer. . Further, it may be configured as a signal that can be regarded as a computer program for causing a computer to perform a route search. Further, it may be configured as a recording medium recording these computer programs.

Here, as the storage medium, a flexible disk, a CD-ROM, a magneto-optical disk, an IC card,
Various computer-readable media such as ROM cartridges, punched cards, printed materials on which codes such as bar codes are printed, internal storage devices (memory such as RAM and ROM) of computers, and external storage devices can be used.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described based on an example of a route search device. A. Route search device: B. Four-point regulation: C.I. Label data corresponding to link: D. Route selection based on factors other than cost:

A. Route Search Device: FIG. 2 is a schematic configuration diagram of the route search device. The route search device 100 uses wireless communication or a CD (Compact Disk) or the like,
Acquires the map data that identifies the graphs and regulations to be searched. In addition, GPS (Global Position)
Ning System) and other sensing devices can be used to compare map data with one's own position. The user operates the remote controller 103 or the operation panel 10
It is possible to cause the route search device 100 to perform a route search by using 1 or the like. The route search device 100 is a display device 1
02, and outputs the route search result to the user.

FIG. 2 also shows the functional block configuration of the route search apparatus 100. The route search device 100 is a CPU
Further, the control unit 200 is configured as a microcomputer including a memory and the like, and the functional blocks illustrated in the figure are configured as software as the functions of the control unit 200. However, each functional block may be configured by hardware. Although the control unit 200 shown in FIG. 2 is shown as being integrally configured, a plurality of devices that communicate with each other may constitute the control unit 200 as a whole. For example, it may be physically separated into two locally connected devices, or may be configured using another network.

The map data input unit 201 has a function of inputting map data. The map data includes graph data regarding nodes, links, costs and other information as shown in FIG. The map data also includes regulation data. The regulation data is data that specifies regulation of the passage method in the graph. Note that the map data may include various kinds of information in addition to the above. For example, the facility information associated with the graph may be included. Also, the map data input unit 2
01 may input map data using an information storage medium such as a CD, or may be input via the Internet, a wireless network or other networks.

The map storage unit 400 includes a map data input unit 2
The graph data and regulation data input by 01 are stored.
A part of the map storage unit 400 is configured as a regulation information storage unit 410 and stores regulation data.

The position information input section 202 inputs information on the current position. The position information is generated by the GPS function. It is also generated by the functions of other sensing systems. Regarding the latter function, for example, in the case of a car navigation system mounted on a vehicle, the position information input unit 202 inputs position information based on a rotation sensor provided on an axle or a steering wheel of the vehicle.

The user input section 220 inputs a user input via the remote controller 103. User input is also given based on the operation panel 101, and the user input unit 220
Also enter this (not explicitly shown in the figure). The user can execute a route search by using the remote controller 103 or the operation panel 101. Further, it is possible to input a search condition such as a starting point or a destination in the route search. For example, it is possible to specify whether or not to adopt the current position indicated by the position information input by the position information input unit 202 for the departure point of the searched route.

The route search unit 300 includes a user input unit 220.
The route search is performed based on the search instruction received from the. At this time, the graph data and the regulation data are received from the map storage unit 400, the position information is received from the position information input unit 202, and these are used. The route search unit 300 generates and stores label data including cost information of a candidate route and previous route information for use in route search. Route search unit 300
Of the label holding unit 310 and the search processing unit 311.
Is configured as. These will be described later.

The display control unit 210 has a display control function, and by outputting the search result of the route search unit 300 to the display device 102, it can be provided to the user.

FIG. 3 is a schematic configuration diagram of data used in the route search device. The graph used in FIG. 1 is reproduced here. Details of the storage performed by the map storage unit 400 will be described below using this graph. In the graph shown in FIG. 3, the label L1 and the label L2 are assigned to the node B.
Is attached. This shows an example of label data used in the search processing in the route search unit 300. Label data generated and stored by the route search unit 300 in the search process using the labels L1 and L2 in FIG. 3 will be described. Here, in the graph shown in FIG. 3, costs corresponding to each link are shown in parentheses.

A part of the map storage unit 400 is a node storage unit 420, a link storage unit 421, and a regulation information storage unit 41.
Configured as 0.

The node storage unit 420 stores the nodes of the graph as schematically shown in the figure. The names of the graph nodes are stored in the columns of the table. It should be noted that the attribute of the node, the link name connected to the node, the label name given to the node, the related regulation name, etc. may be stored together.

The link storage section 421 stores, for each link, a name, a name of two nodes as endpoints, and a cost value given to the link as a set. Although the order of the two nodes as the end points is not taken into consideration in the present embodiment, for data including so-called directed links, it is sufficient to store information about that and the order of the nodes.

The regulation information storage unit 410 stores regulation data regarding regulation of passages. As described above, the graph shown in FIG. 3 has a right-turn prohibition restriction on the routes A → C → D. Such restrictions can be specified by three ordered nodes. Therefore, the regulation information storage unit 41
0 indicates such a three-point regulation (hereinafter, such regulation is called a three-point regulation) as a set of data of a name “M”, a type “three-point regulation”, and a regulation content “A⇒C⇒D”. Remember.

The three-point regulation can be specified by two links other than by three nodes.
In this case, in the example in the figure, regarding the regulation content, “A⇒C
It is conceivable to store "q⇒s" instead of "⇒D". It is useful to employ such a data structure when the route search unit 300 generates and stores label data according to a link and performs a search, as in an embodiment described later.

Since there are various restrictions, the data structure of the "regulation details" column in the restriction information storage unit 410 can be variously used. For example, four-point regulation similar to the three-point regulation may be made available, as will be described in detail in Examples described later.

The route search unit 300 has a label holding unit 310 that functions as a label information storage unit and a search processing unit 311 that functions as a selection unit and a search execution unit.

The label data holding unit 310 holds label data used to manage candidate routes in the course of route search to a destination. The label information included in the label data includes the total cost of the candidate routes and the immediately preceding node name as the immediately preceding route information. By comparing the immediately preceding route information with the regulation information, it is possible to judge whether or not the regulation prevents further extension of the candidate route. The label data may be a candidate label or a definite label. In the label data, the distinction between the candidate label and the confirmed label is recorded.

Here, the label holding unit 310 stores a plurality of label data corresponding to one node and having different immediately preceding route information. Therefore, label data as many as the number of nodes connected to the node can be stored. The label holding unit 310 manages the label data in association with the node and also manages the node according to the immediately preceding route information.

Note that, in FIG. 3, the immediately preceding route information is shown using nodes for convenience of description, but it is sufficient to include the names of labels attached to those nodes, as will be described later.

The search processing unit 311 includes a label holding unit 310.
Operations such as generation / update / deletion of the label for the label are read out, and label information is read to search for the label. In addition, the search processing unit 311 uses the map storage unit 40.
Label processing is performed with reference to the graph data and the regulation data stored in 0.

FIG. 4 is a flowchart of the route search process. FIG. 5 is an explanatory diagram showing the processing of label data. Further, FIG. 6 is an explanatory diagram showing a continuation of the processing shown in FIG. Here, the graphs used for description in FIGS. 5 and 6 are the same graphs as those shown in FIG. 1, and have the same right turn prohibition regulation as in the case of FIG.

Steps Sa01 to Sa03 in FIG. 4 are processes for inputting data. That is, step Sa0
The graph data is input in step 1, the regulation data is input in step Sa02, and the data relating to the nodes of the starting point and the destination are input in step Sa03.

In step Sa11 of FIG. 4, the search processing section 311 initializes the label holding section 310. Here, a definite route with a cost of 0 that departs from the departure node and terminates as it is is generated as label data that is a candidate label. This label data is stored in association with the departure node.

The label La in STEP Sb00 of FIG. 5 is a label generated based on such initial setting. In this label, since the node immediately before the leading edge on the route cannot be considered, the special data “$” is included as the immediately preceding route information.

In step Sa31 of FIG. 4, the candidate route having the lowest cost is searched from the candidate routes. Since such a candidate route is a confirmed route, that label is selected as the label of interest and the candidate label is changed to the confirmed label. Here, the fixed route is a route from the departure node to a specific node, and is a route with the best cost among the routes in which the node immediately before the specific node is the same. It should be noted that the candidate route of cost 0 for generating the candidate label in the initial setting of step Sa11 is an obvious fixed route.

In STEP Sb00 of FIG. 5, the label La is the only label. Therefore, step Sa3
In the process of 1, this is always selected and used as the label of interest and changed to the confirmed label (see STEP Sb01 in FIG. 5).

In step Sa32 of FIG. 4, it is determined whether or not the target route is a route reaching the destination node. If it has reached the destination node, the route search is terminated by using that route as the route of the search result. On the other hand, if the route does not reach the destination node, the label is set as the label of interest and the processes of steps Sa21 to Sa24 are executed.

The node A labeled with La in STEP Sb00 of FIG. 5 is not the destination node. Therefore, steps Sa21 to Sa2 in which the label La is the label of interest
Process 4 is performed.

In the processing of steps Sa21 to 24 of FIG. 4, extension of the candidate route is tried, and whether or not it is possible is examined based on the regulation information, the immediately preceding route information, and the cost comparison. In step Sa21, the node connected to the most advanced node of the candidate route by the link is checked. In step Sa22,
Investigate whether the extension of such a link is out of regulation.

In the processing in steps Sa22 and Sa23, whether or not the route extension is possible is examined with reference to the existing candidate label. In step Sa23, for the extension that does not violate the regulation, it is checked whether or not there is a candidate route having the same previous route information. That is, an existing candidate route that matches the two leading nodes is searched. If it exists, in step Sa24, whether or not the drawing is possible is examined based on the cost comparison with the existing label. The candidate route will not be extended unless cost improvement can be obtained. For this, the cost information included in the label is used as in the case of the normal Dijkstra method. The route extension rejected by the cost comparison is excluded from the target in the label generation process in step Sa25.

In the processing in step Sa25 of FIG. 4, the candidate route is extended based on the above examination. That is, a candidate label is created according to the extended candidate route.

In STEP Sb01 of FIG. 5, the label L
The label Lb and the label Lc are generated using a as the label of interest. The labels are La, Lb, Lc ...
Is added to the beginning of the label. Nodes B and C connected to the node A are detected by the processing in step Sa21 in the flowchart of FIG. Further, in the processing of step Sa22, it is confirmed that the route extension to the nodes B and C does not violate the regulation. Furthermore, step Sa
In 23 to Sa24, the possibility of path extension is examined by collating with an existing label. In addition, STEP Sb of FIG.
In the case of 00, the existing candidate label is only the label a, so that there is no label to be examined here.

By the above processing, STEP Sb of FIG.
As indicated by 01, the label Lb and the label Lc are attached to the nodes C and B, respectively. Both the label Lb and the label Lc include the name of the "label La" as the immediately preceding route information, the node name to which the label is attached, and the information of the total cost of the candidate route specified by each label. Figure 4
The process on the flowchart shown in step S31 returns to step Sa31.

Next, the processing shown in step Sa31 in the flowchart of FIG. 4 is executed again. Here, the label Lb and the label Lc exist as candidate labels, and the label Lb is found as the label with the minimum cost.
Change to the finalized label. As a result, the processing of steps Sa21 to Sa24 in the flowchart of FIG. 4 is performed with the label Lb as the target label.

STEP Sb02 in FIG. 6 is labeled Lb.
5 shows the result of performing the processing of steps Sa21 to Sa24 in the flowchart of FIG.

First, the nodes B and D connected to the node C are detected by the process of step Sa21 in the flowchart of FIG. Here, the node C is also connected to the node A, but “C → A” is registered as a U-turn prohibition registration (that is, C → A → C traffic prohibition registration) as restriction information, and is not covered here. And The fact that C → A → C is prohibited is stored in the regulation information storage unit 410.

Next, by referring to the regulation information in the processing of step Sa22, it is detected that the extension of the candidate route to the node D is against the regulation. At this time, the previous route information included in the label Lb which is the label of interest is referred to. In this example, since the node immediately preceding node C in the candidate route is node A, the route extension to node D is "A →
It is detected that the right turn prohibition regulation of the “C → D” route is violated.
Based on this, in the label creation processing in step Sa25, the one for node D is excluded. On the other hand, since the route extension to the node B is not obstructed by the regulation, it is left as the target of the processing in steps Sa23 to Sa24.

As described above, steps Sa23 to Sa2
In 4, the collation with the existing label is performed and the possibility of route extension is examined. In the example of FIG. 5, whether or not the route can be extended from the node C to the node B is checked by checking with the label Lc that is an existing label.

In the processing in step Sa23, it is examined whether or not there is a label having the same corresponding node and having the same immediately preceding route information. In the present embodiment, although the label Lc having the same corresponding node is found, the presence of the label Lc is not a basis for denying the route extension because the immediately preceding route information is different. In this embodiment,
In order not to find a common label for previous route information,
There is no label for which the cost matching process in step Sa24 is performed. Therefore, step Sa2
Following the collation of the immediately preceding route information in step 3,
The label generation processing in 25 is immediately executed. In step Sa23, if there is a label having the same corresponding node and having the same immediately preceding route information, the cost collation is performed and the label with the high cost is deleted.

As described above, the label Le shown in STEP Sb02 of FIG. 6 is newly created by the processing of step Sa25 based on the examination processing of steps Sa21 to Sa24. The label Le has the label Lb as the previous route information.
However, NB is added as the information indicating the corresponding node, and 3 (= 1 + 2) is added as the cost value.

By the processing up to this point, STEP in FIG.
In Sb02, the label Lc and the label Le are attached to the node B. The label Lc corresponds to the candidate route “A → B”, and the label Le corresponds to the candidate route “A → C → B”. Both have different previous route information,
A plurality of labels corresponding to the same node is configured as label data on the label holding unit 310.

STEP Sb10 of FIG. 6 is labeled Lc.
Shows the result of the process of selecting the label as the target label and attaching the label Lf to the node C. Since the two labels are attached to the node B, the “label c” is set as the target label in the processing in the subsequent step Sa31, and the label L
f can be generated. At this time, since the existing label Lb in the node C does not have the same previous route information, it does not serve as a basis for eliminating the generation of the label Lf in the process of step Sa23 in the flowchart of FIG.

The STEP Sb20 shown in FIG. 6 has a label Lf.
Is selected as the label of interest, and the result of the process of attaching the label Lg to the node D is shown. Step Sa3
By selecting the label Lf as the target label in the process of 1, the label Lg is generated in the process of step Sa25.
Further steps Sa31 and Sa in the subsequent stage
In the process of 32, the definite route reaching the destination is found by selecting the label Lg as the label of interest. As a result, “A →
A route with a cost of “B → C → D” is found, and the process ends.

In this embodiment, the information designating the label attached to the node immediately before the candidate route is used as the immediately preceding route information, but the present invention is not limited to this case. Various kinds of information can be adopted as long as they are immediately preceding route information that specifies a route in a predetermined section immediately before reaching the most advanced node. For example, the nodes and links passed immediately before may be enumerated. Further, when the regulation information is regulation defined by N points (N is a natural number of 3 or more) nodes, the immediately preceding route information can be route information of a section corresponding to the node of N−2 points. .

In this embodiment, the immediately preceding route information is 1 for the graph having the restriction defined by the nodes of 3 points.
Although the case where the route information is the route information of the section corresponding to the node of (= 3-2) is shown, the case is not limited to such a case. For example, 4 defined by a 4-point node
For graphs with point restrictions, the previous route information is 2 (=
4-2) It may be possible that the route information is the route information of the section corresponding to the node at point 4-2). At this time, the immediately preceding route information can be configured by a permutation of two nodes or a link and its direction.

Further, in the present embodiment, the cost is attached only to the link, but the node itself may be attached with the cost.
When adding a cost to this node itself, it is possible to use the presence or absence of a traffic light and the time (including the right turn allowable time) of turning on the blue signal as the basis for the determination.

By using the route search device constructed according to the present embodiment, it is possible to realize a flexible route search technique in the passage having the regulation of the passage method. Even in a graph that has a three-point regulation that is a regulation of the passage method,
It is possible to realize route search based on the principle of cost advantage.

B. Four-point regulation: In the first embodiment, regarding the graph having the regulation defined by three-point nodes, the case where the immediately preceding route information corresponds to the node sequence of 1 (= 3-2) points is shown. In the present embodiment, for a graph having a four-point restriction defined by four-point nodes, the case where the immediately preceding route information corresponds to a node sequence of 2 (= 4-2) points will be described.

As shown in FIG. 7, the four-point regulation prohibits the extension of the route to the node E connected to the node C after taking the route "node A → node B → node C", for example. U-turn to B is also prohibited. In the case of such a regulation, the regulation information can be configured by a permutation of four nodes.

The schematic structure of the route search device and its functional blocks are the same as in the case of the first embodiment (see FIGS. 2 and 3). However, the regulation information in the regulation information storage unit includes four-point regulation. Further, the label data including the immediately preceding route information which is the route information of the section corresponding to the node sequence of two points is generated and used in the label holding unit in the route searching unit. These points are different from the case of the first embodiment.

Here, the immediately preceding route information is shown in the format of listing the nodes, but the label associated with the immediately preceding node may be designated.

In the case of four-point regulation, when enumerating nodes, as shown in the figure, information for identifying at least two nodes is required. On the other hand, in the case of specifying the immediately preceding label, it is possible to recursively identify the routes of two nodes by tracing back the labels in sequence, and thus even in the case of four-point regulation It is enough to specify the previous label. Therefore, there is an advantage that the data amount of the label information can be suppressed by designating the immediately preceding label.

FIG. 7 is an explanatory view illustrating the processing of label data corresponding to the four-point regulation. FIG. 7 also shows a schematic configuration of data used by each functional block in the regulation information storage unit 410a and the label holding unit 310a.

The graph including the nodes A, B, C, D and E of 5 points in the figure has a 4-point restriction. This is the route "A → B
This is a four-point regulation that regulates the extension of the route to the node E following "→ C".

The label holding unit 310a shown in FIG. 7 exemplifies a state in which two labels Lba and Lbd corresponding to the node C are held. Here, the immediately preceding route information of each label is different. The immediately preceding route information in these labels specifies the node sequences of nodes B and A and nodes B and D, respectively. These show partial routes in the candidate route corresponding to each label immediately before reaching the node C.

The graph search processing in the second embodiment is the same as that in the first embodiment (see FIGS. 4 to 6) except for the processing relating to the regulation information and the immediately preceding route information. Therefore, the search process in this embodiment is the same as the process shown in the flowchart in FIG. Therefore, the processing in this embodiment will be described below with reference to the flowchart of FIG. 4 while paying attention to the processing different from that in the previous embodiment.

The initial data input and the initial setting of the label holding section 310a in steps Sa01 to Sa11 are the same as those in the first embodiment. However, the regulation data includes regulation data for four-point regulation.

After that, the process including the label selection process in step Sa31, the process of checking the arrival at the destination node in step Sa32, and the route extension process in Sa21 to Sa25 is repeated. In step Sa32, when the confirmed route reaching the destination node is recognized, the determined route is set as the search result, and the process ends.

In step Sa21, the process of searching for another node connected to the leading node of the candidate route is the first.
This is similar to the case of the embodiment. The regulation information collating process in step Sa22 is different from the case of the previous example in that the process of the present embodiment performs collation on two nodes. Further, the previous route information matching process with the existing label in step Sa23 also differs from the previous embodiment in that the process of the present embodiment performs matching on two nodes. It should be noted that the same immediately preceding route information is determined by whether or not the two points are the same. This is the same as the case of the collation processing with the regulation information. Note that step S
In a24, the cost comparison with the existing label having the same corresponding node and immediately preceding route information is the same as in the case of the first embodiment.

After all, the label producing process in step Sa25 is similar to the case of the first embodiment in that only the labels having different immediately preceding route information are produced. However, based on the processing in step Sa22, only the label that corresponds to the route extension that complies with the four-point regulation is created.
Further, based on the processing in step Sa23, the label creation processing is performed when one node is different from that in the first embodiment in that the label creation is performed when the two immediately preceding nodes are different. Be different. Further, the label data creating process in step Sa25 is a creating process of the label data including the information of the two nodes as the immediately preceding route information, which is different from the case of including the information of the one node in the first embodiment.

Here, two labels Lba and Lb corresponding to the node C illustrated in the label holding unit 310a of FIG. 7 are used.
Consider d. Step S based on these labels
The path extending process of a21 to Sa25 is performed in step Sa31.
This is done by selecting these labels as the label of interest in the processing in (1).

The detection of the node E connected to the node C in step Sa21 is the same for any label. In step Sa22, by referring to the regulation information storage unit 410a, it is determined that the route to the node E cannot be extended for the candidate route specified by the label Lba. As a result, the remaining steps Sa2
The label creation processing in 4 to Sa25 is suppressed. In the case of the label Lbd, it is recognized that the route extension complies with the regulation, and the matching process with the existing label in steps Sa23 to Sa24 is performed. After this, step Sa2
At 5, label generation is performed and path extension to the node E is executed.

By using the route search device constructed according to the present embodiment, it is possible to realize a flexible route search technique in the passage having the regulation of the passage method. Even in a graph that has a four-point regulation that is a regulation of the passage method,
It is possible to realize route search based on the principle of cost advantage.

C. Label corresponding to a link: In the above-described embodiment, the label data is configured corresponding to the node. By the way, a link is a permutation of two nodes, and it is also possible to perform a route search in which label data is generated and used corresponding to the link. In the following, a case where label data corresponding to a link is used will be exemplified.

FIG. 8 is an explanatory view illustrating the processing of label data corresponding to a link. The graph shown in FIG. 8 is the same as the graph of FIG. 7 used in the description of the second embodiment, although the form is changed for convenience of description. Here, in the graph of FIG. 8, not only the nodes and links are the same as those in the second embodiment, but the four-point regulation “A⇒B⇒
The same applies to "C⇒E". For convenience of illustration, the links AD, AB, BD, BC, and E are shown here.
"P", "q", "r", "s", "t" for C respectively
The explanation will be given with a new name.

The schematic configuration of the route search device and its functional blocks are the same as in the case of the second embodiment in the case of the present embodiment.
It is equivalent to that shown in the first embodiment. However, the regulation information in the regulation information storage unit 410b in the present embodiment uses the regulation information that specifies the regulation by using the link. Further, as the immediately preceding route information, information for identifying the immediately preceding route using a link is used.

In this embodiment, the regulation information storage unit 410b identifies the four-point regulation (three-link regulation) by using the regulation data of the link permutation "q → s → t". Further, the label data in the label holding unit 310b is the label data including the link name for the corresponding element and the immediately preceding route information. Label data is generated corresponding to a link.
That is, the candidate route is grasped as a sequence of links, and the candidate route is managed by using the label corresponding to the leading edge link of the link sequence. For the last-minute route information, use the link immediately before the leading edge. However, this is to specify the two nodes included in the immediately preceding route information in the second embodiment by one link connecting them.

In the label holding unit 310b of FIG. 8, two labels Lq and Lr corresponding to links are illustrated.

These labels show candidate labels corresponding to two candidate routes to the node C. By referring to the immediately preceding route information, the route at the leading edge of the candidate route can be identified as “D → B → C” with the label Lr and “A → B → C” with the label Lq. This allows
It can be specified that the candidate route at the label Lq cannot be extended to the node E via the link q.
The route information of the section corresponding to two nodes preceding the most advanced node of the candidate route can be specified by referring to the link included in the immediately preceding route information. In this embodiment, the same route search processing as in the second embodiment is performed by using the label data schematically shown in FIG.

The graph search processing in this embodiment is the same as that in the second embodiment. Hereinafter, the processing in the present embodiment will be described with reference to the flowchart of FIG. 4 showing the processing in the first embodiment, paying attention to the points different from the case of the second embodiment.

Label production in step Sa25
This is the creation of the label corresponding to the link. That is, the label is created corresponding to the leading edge link in the candidate route.
Therefore, in the regulation information collating process in step Sa22, the same link strings are collated. The same applies to the collation process of the immediately preceding route information in step Sa23. For the label of interest and the existing label, the same link string included in the immediately preceding route information is checked.

By using the route search device constructed according to the present embodiment, it is possible to realize a flexible route search technique in the passage having the regulation of the passage method. Even in the graph having the three-link regulation which is the regulation of the passage method, the route search based on the principle of cost advantage can be realized. Flexible processing can be performed using various data structures according to the nature of the route. Efficient search processing can be realized by integrated management of node data based on link data.

In the above description, the route search device is the CD
The map data storage device such as ROM and the search result display device are integrally provided, but the present invention is not limited to such a case. Hereinafter, a modified example using a network such as a local connection, the Internet, and a wireless LAN will be described.

For example, first, the map data may be acquired via a network. Secondly, display control data may be sent to provide search result information or obtain user input by connecting to an external device operated by the user via a network. Third, the search processing is performed based on the map data acquired via the network, and
A mode in which the search result is also sent via the network is also conceivable. Further, the acquisition source of the search instruction and the destination of the search result may be different. In the modified example described above, the search process such as the label operation can be flexibly selected and used as the search process of the first to third embodiments. For example, although A → C → A is prohibited in the first embodiment, it may be used when it is not prohibited.

D. Route selection based on factors other than cost:
In the embodiment, the case where the traffic regulation is provided as an element to be considered in order to select a route other than the magnitude relation of costs has been illustrated. INDUSTRIAL APPLICABILITY The present invention can be used for route search considering various factors regardless of traffic regulations.
Examples of such factors include driver preference and safety such as straight ahead priority and national road priority.

FIG. 9 is an explanatory view showing an example of route search in consideration of straight line priority as a modification. In the graph shown in FIG.
The nodes, the links, and the costs attached to the links are the same as those shown in FIG. 3 in the description of the first embodiment. The graph shown in FIG. 9 differs from the case of FIG. 3 in that the cost corresponding to the passage direction is set in the node C.

The cost corresponding to the passing direction is the cost indicating the straight line priority. For example, for a route that goes straight through the node C, such as nodes B → C → D, the cost value 1 for straight going is applied. A cost value 7 for right turn is applied to a route that passes through the node C by making a right turn, such as nodes A → C → D.

The label holding unit 310c of FIG. 9 uses two types of candidate routes A → C and A → B → C in the process of route search.
The labels Lca and Lcba corresponding to and are stored. When the extending direction from the node C is undecided, the straight travel cost and the right turn cost are not reflected, so the cost value of the label Lca is 1 and the cost value of the label Lcba is 5. In the extension to the node D, the cost of going straight and turning right is calculated from the immediately preceding route information included in the label, and the candidate routes are compared. As a result, the route “A → B → C → D” based on the straight-ahead priority condition is obtained.

FIG. 10 is an explanatory diagram showing a route search example in which priority is given to national roads as a modification. In the graph shown in FIG. 9, four links A → B, B → C, C → D, D → E represent national roads. The links B → D and D → F represent normal roads.

Here, in general, when merging from a normal road to a national road, there is danger, it takes time,
Often requires attention. Therefore, as a cost that represents such a situation, the node B is connected to the route B of the national highway.
The cost value 3 for → D → E is set.

As a result of the route search, two routes A → B → D,
Consider the case where the costs for A → B → C → D are calculated and two labels corresponding to these routes are attached to the node D. When the extension direction from the node D is undecided, the cost of merging national roads is not reflected. Therefore, route A
The cost of → B → D is 4, and the cost of A → B → C → D is 5.

When the extension to the destination E is carried out in this state, the cost value 1 of D → E and the cost value 3 of the confluence of national roads are reflected on the route A → B → D. It becomes 8. Since only the cost value 1 of D → E is added to the route A → B → C → D, the total cost is 6. Therefore, the route A → B → C → D → E which gives priority to the national road is obtained as the search result.

As described above, according to the route search device described with reference to FIGS. 9 and 10, by using a plurality of labels generated in association with one node or link,
The route can be searched by extending the route while considering various factors. Although the modification of FIGS. 9 and 10 exemplifies a method in which factors such as straight ahead priority and national road priority are reflected and considered in costs, these factors may be evaluated without being reflected in costs. . For example, in the example of FIG.
As long as there is a straight route, the straight route may be selected regardless of the cost, and the right turn route may be selected only when the straight route is completely impossible.

Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that various configurations can be adopted without departing from the spirit of the present invention. For example, the above processing may be realized not only by software but also by hardware.

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating a passage having a passing method.

FIG. 2 is a schematic configuration diagram of a route search device.

FIG. 3 is a schematic configuration diagram of data used in a route search device.

FIG. 4 is a flowchart of a route search process.

FIG. 5 is an explanatory diagram showing processing of label data.

FIG. 6 is an explanatory diagram showing a continuation of the processing shown in FIG.

FIG. 7 is an explanatory diagram illustrating the processing of label data corresponding to the four-point regulation.

FIG. 8 is an explanatory diagram illustrating the processing of label data corresponding to a link.

FIG. 9 is an explanatory diagram showing an example of a route search considering straight line priority.

FIG. 10 is an explanatory diagram showing an example of a route search in which priority is given to national roads.

[Explanation of symbols]

100 ... Route search device 101 ... Operation panel 102 ... Display device 103 ... remote control 200 ... Control unit 201 ... Map data input section 202 ... Position information input section 210 ... Display control unit 220 ... User input section 300 ... Route search unit 310 ... Label holder 311 ... Search processing unit 400 ... Map storage unit 410 ... Regulation information storage unit 420 ... Node storage unit 421 ... Link storage unit 410a ... Regulation information storage unit 310a ... Label holder 410b ... Regulation information storage unit 310b ... Label holder 410c ... Regulation information storage unit 310c ... Label holder 410d ... Regulation information storage unit

Continued front page    F term (reference) 2C032 HB05 HB22 HB25 HC08 HC15                       HD16 HD23                 2F029 AA02 AB01 AB07 AB13 AC02                       AC09 AC14 AC16 AC20                 5H180 AA01 BB13 CC12 FF04 FF05                       FF12 FF13 FF22 FF27 FF32

Claims (10)

[Claims] 1. A route search device for performing a route search, the route data storage unit storing route data represented by nodes and links as elements, and associated with at least one of the respective nodes and links. A cost storage unit that stores costs, an instruction input unit that inputs an instruction to select a node corresponding to a departure place and a destination, and a destination from the departure place based on the stored contents of the passage data storage unit and the cost storage unit. And a route search unit that searches for a route to the ground, wherein the route search unit, for a node on a plurality of candidate routes, at least one of a transit node and a transit link that have elapsed from the point of departure to the node. A label information storage unit that generates label information representing the integrated value of the associated costs and stores the label information in association with the node, and the size of the integrated cost value. A selection unit that selects any one of the candidate routes based on the selection, a label information storage unit, and a search execution unit that repeatedly uses the selection unit to search for a route to the destination, the label information The storage unit can store two or more pieces of label information in association with the node, and when storing two or more pieces of label information, immediately preceding route information for specifying a route in a predetermined section immediately before reaching the node. To
A route search device that stores the label information. 2. A route search device for performing a route search, the route data storage unit storing route data representing nodes and links as elements, and at least one of the nodes and links. A cost storage unit that stores costs, an instruction input unit that inputs an instruction to select a node corresponding to a departure place and a destination, and a destination from the departure place based on the stored contents of the passage data storage unit and the cost storage unit. And a route search unit that searches for a route to the ground, wherein the route search unit, for a node on a plurality of candidate routes, at least one of a transit node and a transit link that have elapsed from the point of departure to the node. A label information storage unit that generates label information representing the integrated value of the associated costs and stores the label information in association with the node, and the size of the integrated cost value. A selection unit that selects any one of the candidate routes based on the selection, a label information storage unit, and a search execution unit that repeatedly uses the selection unit to search for a route to the destination, the label information Is a route search device including immediately preceding route information for specifying label information corresponding to a node immediately before reaching the node. 3. The route search device according to claim 1, further comprising: a regulation information storage unit that stores regulation information about a passage method for at least some of the nodes, and the selection unit includes the regulation information. A route search device that performs the selection in consideration of the above. 4. The route search device according to claim 3, wherein the regulation information is a regulation defined by nodes of N points (N is a natural number of 3 or more), and the immediately preceding route information is N− A route search device that is route information of a section corresponding to two nodes. 5. The route search device according to claim 1, wherein the label information storage unit suppresses generation of label information in which at least a part of the immediately preceding route information overlaps. 6. A computer program for causing a computer to perform a route search, comprising a passage data storage function for storing passage data represented by nodes and links as elements, and at least one of the respective nodes and links. Based on the cost storage function of storing the associated cost, the instruction input function of inputting an instruction to select the node corresponding to the departure point and the destination, and the storage content of the passage data storage function and the cost storage function And a route search function for searching a route from a departure place to a destination, wherein the route search function is, for a node on a plurality of candidate routes, an elapsed node and an elapsed link that have passed from the origin to the node. Label information that represents the integrated value of costs associated with at least one of the A label information storage function, a selection function that selects one of the candidate routes based on the magnitude relation of the cost integrated value, a route to the destination by repeatedly using the label information storage function and the selection function. The label information storage function is capable of storing two or more pieces of label information in association with the node and storing two or more pieces of label information in the node. The immediately preceding route information that specifies the route of the predetermined section just before reaching,
A computer program stored in each label information. 7. A computer program for causing a computer to perform a route search, comprising a passage data storage function for storing passage data represented by nodes and links as elements, and at least one of the respective nodes and links. Based on the cost storage function of storing the associated cost, the instruction input function of inputting an instruction to select the node corresponding to the departure point and the destination, and the storage content of the passage data storage function and the cost storage function And a route search function for searching a route from a departure place to a destination, wherein the route search function is, for a node on a plurality of candidate routes, an elapsed node and an elapsed link that have passed from the origin to the node. Label information that represents the integrated value of costs associated with at least one of the A label information storage function, a selection function that selects one of the candidate routes based on the magnitude relation of the cost integrated value, a route to the destination by repeatedly using the label information storage function and the selection function. And a search execution function for searching for the label information, the label information including immediately preceding route information for specifying label information corresponding to a node immediately before reaching the node. 8. A computer-readable recording medium in which the computer program according to claim 6 or 7 is recorded. 9. A method for performing a route search using a computer, comprising: a path data storing step of storing path data represented by nodes and links as elements; and associating with at least one of the respective nodes and links. A cost storage step of storing the obtained cost, an instruction input step of inputting an instruction to select a node corresponding to a departure point and a destination, and a departure point based on the stored contents of the passage data storage step and the cost storage step. To a destination, a route search step of searching for a route from the departure point to the node, and Label information storing step of generating label information representing the integrated value of costs associated with one side and storing the label information in association with the node And a search step of searching for a route to the destination by repeatedly using a selection step of selecting one of the candidate routes based on the magnitude relation of the cost integrated value, the label information storage step, and the selection step. In the label information storing step, it is possible to store two or more pieces of label information in association with the node, and in the case of storing two or more pieces of label information, a predetermined section immediately before reaching the node. Route information immediately before specifying the route of
A method of storing by including it in each label information. 10. A method for route search using a computer, comprising: a route data storing step of storing route data represented by nodes and links as elements; and associating with at least one of the respective nodes and links. A cost storage step of storing the obtained cost, an instruction input step of inputting an instruction to select a node corresponding to a departure point and a destination, and a departure point based on the stored contents of the passage data storage step and the cost storage step. To a destination, a route search step of searching for a route from the departure point to the node, and A label information storage unit that generates label information representing the integrated value of costs associated with one side and stores the label information in association with the node. , A selection step of selecting any of the candidate routes based on the magnitude relation of the cost integrated value, the label information storage step, and a search for searching for a route to the destination by repeatedly using the selection step. A route search device, wherein the label information includes immediately preceding route information that specifies label information corresponding to a node immediately before reaching the node.