JP2001050770A - Traffic network route searching method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently search by giving a number to the node of each mesh formed by dividing a traffic network, giving adjoining mesh joint data to the node on a compartment side, and again searching for the route of the node shown by the joint data when the node changed to a permanent label is on the compartment side. SOLUTION: A traffic network is mesh-likely divided, and a node is let correspond to a specific point. A line connecting the nodes is expressed as a link, and when the link exceeds a mesh boundary, a node is set on the mesh compartment side and a number is given to each mesh. As to the node on a compartment side, adjoining mesh joint data given to the node on the compartment side of adjoining meshes is given. When a node changed to a permanent label is a node on a compartment side during processing route search by a label ascertaing method, for the node shown by the joint data, route search process is added again to be performed. In the joint data, it is described that which nodes of which meshes are the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system for searching for a route from a departure point to a destination point in a transportation network including transportation means under a minimum cost condition.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for route searching in mobile terminals. In a complex transportation network, finding an optimal route is not easy. When the network becomes complicated, the calculation time increases even with a high-performance computer, and the processing becomes practically impossible.

Various methods have been proposed in order to cope with such a situation in which calculation is substantially impossible. The label determination method, which is often used in the shortest route search using a computer for a traffic network, requires a short processing time of the computer, and provides a quick response. Hereinafter, this label determination method will be briefly described. The label determination method is sometimes called the Dijkstra method in the name of the inventor of this method.

[0004] The label determination method will be described using a system represented by a network as shown in FIG. 1 as an example. A circle in the figure corresponding to a specific point is a “node”, and a line connecting the nodes corresponds to a route between the points, and is called a “link”. Mathematically, the set of these nodes and links is called a graph,
A link with a direction is called a directed graph, and a link without a link is called an undirected graph. The example of FIG. 1 is an example of a directed graph. In such a system, the problem of finding the shortest path from the starting point node s to the destination point node t is the shortest path problem.

Now, the shortest path P from node s to node t
Let P = {s, i, j,..., K, t}. At this time, P1 and P1
When divided into two, the subsets P1 and P2 are also the shortest paths in the respective sets. This is called the principle of optimality. An algorithm that mathematically finds the shortest path using this principle is a label determination method. In other words, the label determination method starts with an empty set, assigns temporary labels to the nodes, finds the shortest path nodes one by one, expands the shortest path subset, and finally labels all the nodes. This is a method to determine the shortest route by fixing it to a permanent label. The following is the algorithm when programming on a computer.

The set of all nodes from node s to node t is V, the length d (j) of the shortest path from node s to node j, the set of nodes on the shortest path is S1, and its complement is S2. (= V−S1), the shortest path is obtained by the following method. (1) As initialization, S1 ← 0 (empty set), S2 ← V d (s) ← 0, d (i) ← ∞. Here, i is a node included in the complement set S2 of the shortest path node, and X ← Y represents replacing X with Y.

(2) If S1 = V, the calculation is completed. (3) If S1 ≠ V, the shortest path length d (i) is selected, and v ← i. Since the length d (v) is the shortest path from the node s to the node v, the node v is included in the shortest path node set S1, and the node v is a complement set S2 of the shortest path node.
Remove from

(4) Link exiting from node v (outgoing link)
Calculates d '(i) ← d (v) + avi for all the nodes i included in the complement S2 of the shortest path nodes that arrive next, and if d (i)>d' (i) Let d (i) ← d ′ (i) and p (i) ← v. Here, avi is the length from the node v to the node i (the length of the link), and d (i) and d '(i) are the lengths of the path from the starting point s to i. D at this point
(I) is the shortest path length from a node in the shortest path node set S1. Although there is a possibility that a shorter path exists in the complement set S2 of the shortest path node, it is obtained in the repeated calculation. (5) Return to step (2).

If p (i) obtained by the above method is traced back from the last node t based on p (t),
The shortest path to the departure node s is obtained. For example, when the example of FIG. 1 is obtained by the above algorithm, d (1) = 0 d (2) = 50 d (3) = 70 d (4) = 65 d (5) = 85 p (2) = 1 p (3) = 2 p (4) = 2 p (5) = 3.

Since s = 1 and t = 5, node 3 (p (5) = 3) before node 5 and node 2 (p (3) before node 3
= 2), before node 2 we reach node 1 (p (2) = 1), ie the starting point s. That is, the shortest route is 1 → 2 → 3 →
5. Its length is 85 (= d (5)). Node 1
The length d (4) of the path (1 → 2 → 4) from to the node 4 is
After all it is the shortest path length.

It can be seen from a simulation of the route shown in FIG. 1 actually used in the above algorithm.
There is no need to calculate the length d '(4) from the node to the node 4.
That is, if the label determination method is used, the calculation amount is much smaller than the shortest path calculation based on the total combination.

[0012]

The label determination method described in the prior art has a feature that the processing speed is high when a computer is used. In particular, when the starting point and the destination point are determined, the route that reaches the destination point first can be searched as the minimum cost path while sequentially finding nodes having the minimum cost from the starting point by the label determination method. The target cost is specifically assigned a time or a distance, and the "moving time" or the "moving distance" is evaluated.

In many navigation systems, various methods are used as means for solving problems on a computer. However, when searching for a route under the condition of minimum cost, a label determination method is basically used. For example, such a minimum cost route search includes a minimum cost route search using a railway organization and a minimum cost route search system using an automobile.

In a general label determination method, network data to be searched for a route are combined into one. However, it is necessary to use a plurality of divided network data due to a data amount. is there. The present invention relates to a method for performing a route search by a label determination method using a plurality of divided network data.

When implementing a pedestrian navigation system or a car navigation system with a mobile terminal, there are many examples in which the storage area is considerably limited due to the restriction of small size and light weight. Therefore, in order to download and use only the necessary map area, the map data is divided into a mesh structure.

In the case where map data of adjacent areas must be handled individually, in order to perform a route search including data of adjacent mesh areas using the label determination method, it is necessary to define a relationship with adjacent mesh areas. There is. Various methods can be considered for determining the relationship with the adjacent mesh area.
When considering a route search in a small memory capacity of a mobile or the like, it is desirable that data be as small as possible.

An object of the present invention is to provide a method for efficiently searching for a route using a label determination method for traffic network data divided into meshes, and an efficient method for storing data at that time. Aim.

[0018]

Means for Solving the Problems To solve the above problems, the traffic network is data that is divided into meshes, and a route from a departure point to a destination point is defined by using the data. In a traffic network route search method that expresses a traffic network as a link between links and uses a computer to determine the cost by using the travel time or travel distance as a cost by the label determination method, the traffic divided into meshes in the traffic network route search method Network data is represented by nodes corresponding to specific points, and the lines connecting the nodes are represented by links that are paths between the points. If the links cross the mesh boundary, nodes are set on the mesh side. A number is assigned to a node for each mesh, and nodes on the partition edge are assigned to adjacent meshes. If the node changed to a permanent label is a node on the partition edge in the route search process by the label determination method, the data has a number assigned to a node on the partition edge. For the node indicated as data, a process of performing a route search process again is added.

The adjacent mesh joining node data is data describing which node of which mesh is the same node. One piece of data exists for one partition side node. The adjacent mesh code is a code for expressing the above “any mesh”. The adjacent mesh joining node data is a node number for expressing the above “any node”.

In the above method, data can be reduced by using a relative mesh position as the adjacent mesh code or using a specially managed number as a node number on the partition side. .
For example, a node on a section side is notified by a specific range number or a specific serial number.

The present invention employs a method of managing data for each mesh of network data. This is one reason that portable terminal devices with a small memory capacity can copy only in a limited area. For example, in actual Japan's transportation network data, it is difficult to read and use all data even on a personal computer with a large memory capacity. In addition, there are many advantages in performing an actual route search, for example, when searching for large network data by random access, the search time becomes considerably long.

The general label determination method is based on the premise that a route search is performed on one network. However, even if network data is divided for each mesh, the route search is performed by applying the label determination method. be able to

The traffic network data divided into meshes is represented by "nodes" corresponding to specific points, and lines connecting the nodes are represented by "links" which are routes between the points. If the link exceeds the boundary of the mesh, a node is set on the section side.

Each mesh is assigned a mesh code number. Nodes and links are numbered for each mesh. For this reason, the division side nodes are numbered by both adjacent meshes, so that one division side node is given two numbers. It is assumed that each node has mesh code and node number information. In the following description, the potential means the distance or time from the starting point.

Here, the label is defined as (1, p (v)) for each node. l is a link connecting nodes, v is the current target node, p (v)
Is the potential of path v. Note that the potential p
(V) is the total cost of the route from the starting point (departure node) to the node v.

Step 1 (initial value setting) A special temporary label (*, 0) is assigned to the starting node s, and temporary labels (Φ, ∞) are assigned to the other nodes. The meaning of * means that no link comes in because it is a departure node. The meaning of Φ means that no link has reached the node yet. Such nodes are called unsearched. Step 2 (Search Process for Minimum Potential) From the nodes to which the temporary labels have been assigned, a node having the minimum potential is searched for, and this is set as the minimum potential node v.
If the node v having the minimum potential is the target node, the process ends. Otherwise, among the nodes of the temporary label, the node v having the minimum potential is obtained, and the process proceeds to step 3. Step 3 (Route search processing) The destination node connected by the link a exiting from the node v is δ-
a, assuming that the cost involved is d (δ−a) and the potential of the node v already obtained from the starting point is p (v), the potential of the node δ−a is p (v) + d ( a) Assuming that the potential already set for the node δ-a is p (δa), p (v) + d
If (a) is smaller than p (δ-a), p (v) + d (a) is set to a new potential p (δ-a), and the temporary label is set to (a, p (δ-a)). After performing the above processing,
Let the temporary label of node v be the permanent label. Thereafter, if the node v is a section side node, the process returns to step 4; otherwise, the process returns to step 2 (minimum potential search process). Step 4 (adjacent mesh connection / route search processing) The node indicated by the adjacent mesh connection node of the node v is set to v, the path search processing is performed in the same manner as in step 3 described above, and the process returns to step 2 with the label of the node v as a permanent label. .

Step 5 (End Processing) v is permanently labeled, and a permanent label is output from v in a required format by following the reverse route to the starting point.

In the present invention, since the traffic network data is managed for each mesh, it is necessary to know which node on the division side connects to which node on which division of which mesh, Are provided with adjacent mesh joining node data in advance.

The traffic network data used in the present invention is divided into a plurality of meshes. As an example of such divided data, JIS-X0410-1976 “Region mesh code” will be described. In the JIS "Region Mesh Code", the whole of Japan is divided into longitude and latitude meshes, and a code is assigned to each mesh.

The code indicating the mesh section is a combination of a two-digit number indicating the frequency obtained by multiplying the southern latitude of the section by 1.5 times and a two-digit number obtained by subtracting 100 from the number indicating the west longitude, in this order. Expressed as a four-digit number. For example, the code of a section whose latitude at the south end is 36 degrees north latitude and 142 degrees west longitude is 142 degrees east is 5442.

One of the above meshes (primary area division)
Is further divided into eight equal parts vertically and horizontally, and subdivided into 64 secondary meshes (secondary area divisions). The code indicating the secondary mesh is expressed by the primary mesh in the meridian direction and the latitude line direction.
Numbers from 0 to 7 from the south for the meridian direction and the numbers from the west for the latitude line direction were added to each section obtained by dividing equally, and these were combined in the order of the numbers attached to the meridian direction and the numbers attached to the latitude line direction Two-digit number. One side is about 10km.

Further, the secondary mesh is equally divided vertically and horizontally into ten pieces to create 100 tertiary meshes (tertiary area divisions). The area of this mesh is about 1 km square. In car navigation systems and the like, the use up to the secondary mesh is common. The secondary mesh code consists of the primary area and the secondary
It is a combination of numbers indicating the next area block.

Normally, a personal computer handles data in byte units with 8 bits as 1 byte. Further, in order to extract necessary parts by masking the bit data, an arithmetic operation is performed by substituting the data into an integer variable. Therefore, it is suitable to store data in 2 bytes or 4 bytes. The adjacent mesh joining node data is data describing which node of which mesh is the same node. One piece of data exists for one partition side node. The adjacent mesh code is a code for expressing the above “any mesh”. The adjacent mesh joining node data is a node number for expressing the above “any node”. Here, the adjacent mesh code can be stored at a relative position of 4 bits, and the adjacent mesh joint node data can be stored at 12 bits for one partition side node. If the adjacent mesh joining node data is 12 bits, it can handle up to 4096 partition side nodes.

For example, even if there are roads at 30 m intervals with a relatively large mesh of 10 km square per mesh, there are only about 300 per side of the section, so that the total of all four sides of the mesh is only 1200, which is sufficient. is there. Incidentally, since the average per secondary mesh is about 10 km, 2-byte data is sufficient.

In the secondary mesh classified by JIS, 523667 near Nagoya has the largest number of nodes. This mesh has about 18500 nodes and about 61300 links. The number of parcel nodes is 5
There are 532 pieces in 23657. Therefore, if 10 bits (up to 1024) can be secured for the number of partition nodes, it can be said that 4096 can be secured if 12 bits are provided considering the margin.

As shown in FIG. 2, the area for storing the adjacent mesh joining node data is as follows (the number of nodes to be stored).
X (data capacity of one adjacent mesh junction node). Perform a comparison of each and a comprehensive comparison. In a general data structure, if adjacent nodes are provided with adjacent mesh joining node data, all nodes other than the partition side nodes will secure an unnecessary area. If this unnecessary area is omitted, data can be efficiently stored.

In other words, the average n
If there are nodes and there is a network almost like a grid, the number of nodes in the mesh is n ² . At that time, there are 4n partition edge nodes on four sides, so n ²
This means that -4n units have secured a meaningless area. In the secondary mesh in the downtown area, there are about 18000 nodes per mesh, and there are about 500 partition side nodes, so 97% of nodes can secure meaningless areas.

Next, the capacity of one adjacent mesh joining node data will be described. A general road network structure has adjacent mesh codes and node numbers of adjacent meshes. If each node has a mesh code and a node number, the capacity required for adjacent mesh junction node data is (number of nodes) × (number of mesh code bytes +
Node number byte number). In the case of JIS, the mesh code is a 6-digit number as specified in JIS-X0410-1976, so a minimum of 4 bytes is required. However, this is an integer representation, and requires 6 bytes for character representation.

For example, when there are 18000 nodes as described above, a capacity of 18000 × (4 + 2) = 108000 bytes is required when the mesh code is a 4-byte integer and the node number is a 2-byte integer.

In the method used in the present invention, the mesh number is stored in a relative position of 4 bits, and the node number need only be the node number of the partition side node.
As described for the secondary mesh sectioned by, only 12 bits are required. Therefore, the adjacent mesh joining node data requires only 16 bits, that is, 2 bytes for one partition side node. In addition, since these pieces of data only need to be held by the partition side nodes, if the number of partition side node data is 500, 500 × 2 = 1000 bytes is sufficient, and compression 100 times or more is possible.

From the above, the adjacent mesh joining node data for one node conventionally required a minimum of 6 bytes, but now has 2 bytes, and this data is provided only to the partition side nodes. As shown, compression is realized in the vertical and horizontal directions.

Next, a description will be given of adjacent mesh joining node data using a simple network. In the example illustrated in FIG. 4, the mesh 533934 has six partition side nodes, and has two nodes other than the partition side nodes. There are nine meshes, including the surrounding mesh. For example, the adjacent mesh joining node data of node 126 of mesh 533934 is mesh 5
Node 374 of 33933.

For the codes of the adjacent meshes, the upper, lower, left and right adjacent mesh codes can be easily calculated by the JIS numbering method. For example, the right of 533936 is 5339
37, the lower left is 533925.

An example of a method for storing adjacent mesh joining node data will be described. 4 for one parcel node
As bit data, data in the mesh adjacent to the relative mesh position is stored as shown in FIG.

The adjacent mesh code only needs to be able to express where it is located up, down, left, or right when viewed from its own mesh. Two specific examples are shown as a method of expressing the relative position.

In the example shown in FIG. 6, the four bits in FIG. 5 are assigned to the upper, lower, left and right bits from the front. For example, in the case of the upper right, since the binary number is 1001, the adjacent mesh code is 9. Below is 0100, so it is 4.

In the example shown in FIG. 7, the number is simply assigned from the lower left. If the map data is not connected from corner to corner of the mesh,
Since it is not necessary to express the lower right and lower left, 4
Only three bits are required to represent the direction.

The adjacent mesh joint node data is the number of the same partition side node that overlaps and is assigned to an adjacent mesh. In general, node attributes are rarely given to node numbers themselves, and data areas are often secured by separately using node attribute storage areas for classification. Giving it to the node number itself means that the attribute can be understood just by looking at the node number.

The node number itself has an attribute indicating whether or not the node is a partition side node, and the meshing node data can be efficiently stored by the numbering method. Specifically, the nodes from what number to what number nodes are section side nodes.

The nodes are classified into partition side nodes and other nodes, and the partition side nodes are collected so as to be managed by serial numbers. The simplest method is to collect the nodes of the parcel nodes at the forefront, assign node numbers from 0, and manage them consecutively, and connect the nodes other than the parcel nodes to the end and number them. Is the way. Of course, the data of the section side nodes may be collected later. In any case, it suffices if the data of the section side nodes can be managed by serial numbers.

When mesh codes of the respective parts of the divided map data are regularly assigned, adjacent meshes are obtained by calculation.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described using a road network network as shown in FIG. 8 as an example. Mesh5339
The node 5 of 35 is a departure place, and the node 3 of a mesh 533934 is a destination. Mesh 53 as a representation of node number
If it is node 5 of 3935, it is expressed as 533935.

Step 1: Departure point 533935 (*, 0) Step 2: Set v to departure point 533935. Step 3: Search for v. Compute the potential of the end node of the link exiting from v. The end nodes of 533935 are 533935, 533935, 533935, and 533935. Since all of these end nodes have not been searched, the potential of the end node is the sum of the costs from the potential 0 + v of v to each end node. Therefore, the potential of each end node is 533935 (533935,6) and 533935 (53
3935, 7), 533935 (533935, 5), 533935 (53
3935, 5). A temporary label is attached to these end nodes. The starting point, v, has potential 0 and goes to step 2 as a permanent label

Permanent label list: $ 533935 (*,
0)｝ Temporary label list: ｛533935 (533935, 5), 533935
(533935, 5), 533935 (533935, 6), 533935
(533935, 7)｝

Step 2: Search for a temporary label having the minimum potential. 533935 (533935, 5)
Is the smallest at potential 5.

Step 3: Search for 533935 which is v. Links from 533935 are 5339352, 533935
3, 5339354. Since the end point node of 5339352 has not been searched, the potential is 5 + 8 = 13. Therefore, 533935 (533935, 13) is registered as a temporary label. Similarly, the end node of 5339354 is 533935 (533935
, 8) are registered with the temporary label v. Since the potential of the terminal node of 5339353 has already been determined with a lower potential than this time, a temporary label is not registered. 533935
Goes to step 2 as a permanent label at potential 5.

Permanent label list: $ 533935 (*, 0),
533935 (533935,5)｝ Temporary label list: ｛533935 (533935, 5), 533935
(533935,6), 533935 (533935, 7), 533935
(533935, 8), 533935 (533935, 13)｝ Step 2: The temporary label with the smallest potential is 533935 (533935, 5). Set v to 533935 and go to step 3. Step 3: The link coming out of 533935 is only 53393514, and the end point of the link has a potential of 0, so the temporary label is not registered. 533935 which is v has a potential of 5 and is a permanent label. Here, since 533935 is a section side node, the process proceeds to step 4. Step 4: The adjacent mesh joining node data of 533935 is 533934. The node v is searched with 533934 as v. The link from 533934 is 5339344. Five
Since the end point node 533934 of 339344 has not been searched, the potential is 5 + 5 = 10. Therefore 533934
(533934, 10) is registered as a temporary label. 533934
Goes to step 2 as a permanent label at potential 5. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5)｝ Temporary label list: ｛533935 (533935, 6), 533935
(533935, 7), 533935 (533935, 8), 533934
(533934,10), 533935 (533935, 13)｝ Step 2: Set v to 533935 and go to Step 3. Step 3: The labels after searching for v as 533935 are as follows. Here is the temporary label of 533935
Although it was registered as potential 13 as (533935, 13), the temporary label is 533935 because the potential becomes smaller when going through 533935 by the formula of * 1.
(533935, 10). Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6)｝ Temporary label list: ｛533935 (533935, 7), 533935
(533935, 8), 533934 (533934,10), 533935
(533935, 10)｝ Step 2: Set v to 533935 and go to Step 3. Step 3: The labels after searching for v as 533935 are as follows. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7)｝ Temporary label list ｛533935 (533935,8),
533934 (533934,10), 533935 (533935, 1
0), 533935 (533935, 13), 533935 (533935)
, 14)｝ Step 2: Set v to 533935 and go to Step 3. Step 3: The labels after searching for v as 533935 are as follows. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8)｝ Temporary label list: ｛533934 (533934,10), 533935
(533935, 10), 533935 (533935, 13), 5339
35 (533935, 14)｝ Step 4: v is searched for the adjacent mesh joint node data 533934 of “533935”. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8), 533934 (533935
, 8)｝ Temporary label list: ｛533934 (533934,10), 533935
(533935, 10), 533935 (533935, 13), 5339
35 (533935, 14), 533934 (533934, 15)｝ Step 2: Set v to 533934 and go to Step 3. Step 3: The labels after searching for v as 533934 are as follows. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8), 533934 (533935
, 8), 533934 (533934,10) 仮 Temporary label list: ｛533935 (533935, 10), 533935
(533935, 13), 533935 (533935, 14), 5339
34 (533934, 15), 533934 (533934, 18), 53
3934 (533934, 21)｝ Step 2: Go to Step 3 with v set to 533935. Step 3: The labels after searching for v as 533935 are as follows. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8), 533934 (533935
, 8), 533934 (533934,10), 533935 (533935)
, 10)｝ Temporary label list: ｛533935 (533935, 13), 533935
(533935, 14), 533934 (533934, 15), 5339
34 (533934, 18), 533934 (533934, 21)｝ Step 2: Set v to 533935 and go to Step 3. Step 3: The labels after searching for v as 533935 are as follows. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8), 533934 (533935
, 8), 533934 (533934,10), 533935 (533935)
, 10), 533935 (533935, 13) 仮 Temporary label list: ｛533935 (533935, 14), 533934
(533934, 15), 533934 (533934, 18), 5339
34 (533934, 21)｝ Step 4: v is searched for the adjacent mesh joining node data 533934 of 533935. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8), 533934 (533935
, 8), 533934 (533934,10), 533935 (533935)
, 10), 533935 (533935, 13), 533934 (5339
35, 13) Temporary label list: 533935 (533935, 14), 533934
(533934, 15), 533934 (533934, 18), 5339
34 (533934, 20), 533934 (533934, 21)｝ Step 2: Set v to 533935 and go to Step 3. Step 3: The labels after searching for v as 533935 are as follows. Permanent label list: ¥ 533935 (*, 0), 533935 (53
3935,5), 533935 (533935,5), 533934 (5339
35,5), 533935 (533935,6), 533935 (533935)
, 7), 533935 (533935, 8), 533934 (533935
, 8), 533934 (533934,10), 533935 (533935)
, 10), 533935 (533935, 13), 533935 (5339
35, 14) Temporary label list: ¥ 533934 (533934, 15), 533934
(533934, 18), 533934 (533934, 21)｝ Step 2: Since the node having the smallest potential among the nodes of the temporary label is the target node 533934, the process ends.

The least cost route may be a connection between the destination and the entry node of the permanent label. Label 533934 (533934
, 15), it can be seen that 533934 forms the minimum cost coming from 533934, and the total route cost is 15. Next, the permanent label 533934 of 533934 (533935
, 8) 533934 is the least cost route to enter from 533935. The label for 533935 is 533935 (53
3935,5) means that it enters from 533935. Therefore, the minimum cost route is 533934 ← 533934 ←
533935 ← 533935.

[0059]

The general label determination method is based on the premise that a route search is performed on one network. However, according to the method of the present invention, even if network data is divided for each mesh, the label is determined. Since the route search can be performed by applying the determination method, network data only for the area required for the mobile terminal can be downloaded, and the route search can be performed even with a terminal device having a small memory capacity.

Further, according to the present invention, in storing the data of adjacent mesh junction nodes, there is an effect that the data can be stored with a small data capacity, and a high-speed route search can be performed even if the data becomes large.

[Brief description of the drawings]

FIG. 1 is a network diagram for explaining a method for obtaining an optimal solution using a label determination method.

FIG. 2 is an explanatory diagram of a data area for storing adjacent mesh joining node data.

FIG. 3 is an explanatory diagram of a data area for storing adjacent mesh joining node data.

FIG. 4 is an explanatory diagram of adjacent mesh joining node data.

FIG. 5 is an explanatory diagram of a data structure according to the present invention.

FIG. 6 is an explanatory diagram of an adjacent mesh code.

FIG. 7 is an explanatory diagram of an adjacent mesh code.

FIG. 8 is an explanatory diagram of a road network.

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[Procedure amendment]

[Submission date] August 16, 1999 (1999.8.1
6)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F029 AB13 AC08 5B049 BB31 CC31 EE01 EE05 EE31 GG06 9A001 JJ77 JZ78

Claims (9)

[Claims] 1. A traffic network is data that is divided into meshes. The data is used to represent a route from a starting point to a destination, a point is a node, and a link between points is used to represent a traffic network. In a traffic network route search method for searching under the shortest cost condition using a travel time or a travel distance as a cost using a label determination method, traffic network data divided into meshes includes nodes corresponding to a specific point, The line connecting the nodes is represented by a link that is a route between the points. If the link exceeds the boundary of the mesh, a node is set on the side of the mesh section, and a number is assigned to the node for each mesh. For the nodes on the partition edge, the numbers assigned to the nodes on the partition edge in the adjacent mesh If the node changed to the permanent label is a node on the partition edge in the route search process by the label determination method, the node indicated by the adjacent mesh joined node data of the node is re-routed. A traffic network route search method characterized by adding a process of performing a search process. 2. The traffic network route search method according to claim 1, wherein a relative mesh position is used as said adjacent mesh code. 3. A specially managed serial number is used as a node number on the partition side.
The traffic network route search method described in the above. 4. A traffic network is data that is divided into meshes. The data is used to represent a route from a departure point to a destination, a point is a node, and a link between points is used to represent a traffic network. In a traffic network route search system that searches under the shortest cost condition using travel time or travel distance as a cost by using a label determination method, traffic network data divided into meshes includes nodes corresponding to specific points, The line connecting the nodes is represented by a link that is a route between the points. If the link exceeds the boundary of the mesh, a node is set on the side of the mesh section, and a number is assigned to the node for each mesh. Nodes on the partition edge are assigned to nodes on the partition edge in the adjacent mesh. If the node which has the adjacent mesh joint data which is the number and the node which has been changed to the permanent label in the route search processing by the label determination method is a node on the partition side, the node indicated by the adjacent mesh joint node data of the node is again A traffic network route search system characterized by adding processing means for performing a route search process. 5. The traffic network route search system according to claim 4, wherein a relative mesh position is used as said adjacent mesh code. 6. A specially managed serial number is used as a node number on the partition side.
The traffic network route search system as described. 7. A traffic network is data that is divided into meshes. The data is used to represent a route from a starting point to a destination, a point is a node, and a link between points is used to represent a traffic network. In the traffic network route search that searches under the shortest cost condition using the travel time or travel distance as the cost by the label determination method, the traffic network data divided into meshes is a node corresponding to a specific point, A line connecting the nodes is represented by a link which is a route between points. If the link crosses a boundary of the mesh, a node is set on a side of the mesh section, and a number is assigned to the node for each mesh. For the nodes on the section edge, the number assigned to the node on the section edge in the adjacent mesh is If the node changed to the permanent label is a node on the partition edge in the route search processing by the label determination method, the route search is performed again for the node indicated by the adjacent mesh joined node data of the node. A recording medium for a computer, on which a program for executing a processing procedure is added and executed. 8. The recording medium for a computer according to claim 7, wherein a relative mesh position is used as said adjacent mesh code. 9. The method according to claim 7, wherein a specially managed serial number is used as a node number on the partition side.
The recording medium for a computer as described in the above.