JPH04372985A - Recommended path guiding device - Google Patents

Abstract

PURPOSE:To correctly select a shortest-distance path and a minimum-travel time path in consideration of the loss time for right/left turns and right/left turn prohibitive regulations. CONSTITUTION:A destination and a departure point are selected by a point setting means 101, a search is widened by a link searching means 103 with links from the departure point used as a reference based on the connection information between links stored in a link information memory means 102, the information of the previous link on a path to reach a link and all evaluation values of the distance and time to there are held as a search result for each link, and the path to the destination is searched.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recommended route guidance system that automatically selects and guides a route from one point to another in order to efficiently move a vehicle from one point to another.

0002

[Prior Art] As a conventional route searching device, for example, FIG.
As shown in Figure 8, one cross intersection is divided into eight virtual intersections 3
A method has been reported in which an evaluation value corresponding to loss time when turning right or left at the intersection is expressed by 1. Note that 32 indicates a directed link.

[0003] Also, as a second conventional example, Japanese Patent Laid-Open No. 1-17
There is one disclosed in Japanese Patent No. 3298. FIG. 19 is a block diagram showing the configuration of this second conventional route searching device. In the figure, 801 is a point setting means,
802 is a link information storage means, 803 is a node search means, and 804 is an output means. This is done by setting guidance-unnecessary information in the road data of intersections that can be driven without any special guidance, such as a route that goes straight through an intersection, and expanding the search to each intersection to obtain a certain evaluation without this guidance-unnecessary information. This method attempts to introduce an evaluation value when passing through an intersection by adding the value to the evaluation value of the road. In any of the conventional examples, when expanding the search, the intersection is used as a reference, and for each intersection, the shortest (optimal) route to the intersection is determined.
It left information about the previous intersection on the route.

0004

However, according to the first conventional example, one intersection is divided into eight virtual intersections and 16 virtual intersections.
Since it is expressed as a directed link of a book, calculations for determining whether to turn left or right become complicated, requiring a lot of time and requiring a large amount of data. In addition, according to the second conventional example, the search criterion is set at an intersection,
The road number of the previous intersection on the route from the starting point to each intersection with the minimum evaluation value is recorded for each intersection, so for example, as shown in the road network in Figure 20 (numbers indicate distances). The route from node A to node D with the minimum evaluation value is A-C-D, and link C
If a right turn is prohibited from entering link DE from D, the route A-B-D-E that can reach node E is not retained as data, so there is a problem that the correct route cannot be searched.

[0005] The present invention solves the above-mentioned problems by making it possible to always derive a route if there is a passable route, reliably selecting a route that takes evaluation values at intersections into consideration, and The purpose is to be able to search for recommended routes between starting points and destinations at arbitrary points, not just points.

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the recommended route guidance device of the present invention, the first means stores information on at least one of the direction of a one-way street and the possible direction of travel at an intersection. Then, using that information, the search is expanded based on the link, and the search results are held for each link.

A second method is to determine an evaluation value when passing through an intersection based on the angle of change in direction of travel at the intersection, and add it to the evaluation target.

[0008] Furthermore, the third means is to calculate a departure link approach evaluation value, which is an evaluation value for entering the departure link based on the positional relationship between the departure link and the destination link corresponding to the determined departure point and destination. A target link escape evaluation value, which is an evaluation value for heading from the target link to the destination, is calculated and added to the evaluation target.

[0009]

[Operation] According to the first means, the recommended route guidance device of the present invention provides information indicating the link immediately before the recommended route that reaches the link in order to perform a search based on the link in the link search means. can be saved for each link, so it is possible to always find the correct route even in road networks that include restrictions on turning left and right.

According to the second method, the angle of change in heading direction at an intersection is determined, and an evaluation value corresponding to this angle is added to the evaluation target. It is possible to handle evaluation values according to left turns.

Furthermore, according to the third means, when the departure point and destination are set, the links on the nearest road are determined as the departure link and the destination link, and the departure link entry evaluation value and the destination link escape evaluation value are respectively determined. By calculating and adding it to the evaluation value of the link itself, the total evaluation value from the entry point from the departure link to the exit point of the destination link can be obtained. Recommended routes between locations can be selected.

0012

Embodiments Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram of a recommended route guidance device showing a first embodiment of the present invention. In FIG. 1, 101
102 is a point setting means for setting a departure point and a destination; 102 is a link information storage means for storing various information regarding links;
Reference numeral 103 denotes link searching means 1 for searching for a route between the starting point and destination set by the point setting means 101 using link connection information stored in the link information storage means 102;
04 is an output means for outputting the route obtained by the link search means 103.

The operation of the recommended route guidance device of this embodiment configured as described above will be explained below. FIG. 2 is a diagram showing an example of a road network, FIG. 3 is a diagram showing an example of intersection configuration link information data in this road network, FIG. 4 is a diagram showing an example of link information data in this road network, and FIG. 5(a) ,(b
) is a diagram showing an example of node information data in this road network,
FIG. 6 is a diagram showing an example of right/left turn prohibition information data in this road network, FIG. 7 is a diagram explaining the relationship between link numbers and node numbers in node information data, and FIG. 8 is a diagram showing an example of search result data. 9 is a flow diagram of the recommended route guidance device showing the operation in the first embodiment of the present invention.

First, road data will be explained. As shown in Fig. 2, in the road network represented by 9 nodes A to I and 19 directed links 1 to 19, Fig. 1
As shown in FIG. 3, the link information storage means 102 stores, for each intersection, at least a link that exits from the intersection (hereinafter referred to as an escape link) and a link that enters the intersection in the opposite direction to the escape link. (hereinafter referred to as an approach link), and as shown in Figure 4, each link has information on the starting point intersection, the ending point intersection, and the evaluation value of the link itself. information data, and node information data A (hereinafter referred to as simple nodes) that has information on links in both directions for each road and points at which the links are curved (hereinafter referred to as simple nodes) as shown in FIG. 5(a). If link 2 is composed of nodes "B-n3-n4-n5-C" as shown in 7, and the link in the opposite direction is link 3, △ in FIG. 5(a)
The node information data B shown in Figure 5(b), which has longitude and latitude information indicating where each node, including simple nodes, is located on the map (recorded like mark data), and the node information data B shown in Figure 6. As shown, for each link, right/left turn prohibition information data having information on connecting links that cannot be entered from that link is stored. Furthermore, as the search result data, as shown in FIG. 8, information on the total evaluation value from the starting link to each link, the previous link, and the status of each link is left for each link. Here, the initial values of the search result data are: the total evaluation value is infinite, the previous link is 0,
The status flag is 0. In addition, when there is only one link, link 1, for one-way traffic such as between intersection A and B in Figure 2, the link number is given only to the existing link. 5(a)
For example, the number of the reverse link corresponding to link 1 does not exist in the node information A of . This makes it possible to determine one-way traffic. With the data above, we proceed with the search as follows.

First, in step 301 of FIG. 9, a departure link as a departure point and a destination link as a destination are set and input by the user. Here, this departure link may be the link where the vehicle is currently located. The state flag of the search result data regarding the set departure link is recorded as 1 (a value indicating that it is a candidate state for selection of links that serve as criteria for expanding the search), and the total evaluation value from the departure link is recorded as 0. . Next, in step 302, a link (hereinafter referred to as a reference link) serving as a reference for expanding the search is selected. Among the links in the candidate state, a link for which the minimum total evaluation value is recorded as a search result is searched from the search result information shown in FIG.

FIG. 10 is a detailed flow diagram illustrating the selection of reference links. Hereinafter, according to FIG. 10, step 30 in FIG.
The second process will be explained in detail. First, in step 401, the link data recorded in the search result data is extracted one by one. If the status flag of the link is 1, that is, a candidate state in step 402, the process proceeds to step 403; otherwise, the process proceeds to step 407. In step 403, the total evaluation value of the search result data is read, and in step 404, it is compared with the minimum evaluation value so far (initial value is infinite). If the read total evaluation value is smaller, the process proceeds to step 405; otherwise, Step 407
Move on to processing. In step 405, the minimum evaluation value is rewritten to the read total evaluation value, and then in step 406
to store the reference link as the current link. In step 407, it is determined whether all links have been searched. If the search has not been completed, the process returns to step 401. If the search has been completed, the state flag of the search result data is set to 2 in step 408.
After removing the reference link from the candidate state, the process of step 302 in the flowchart of FIG. 9 is ended.

In step 303, it is determined whether the reference link is the target link. If the reference link is the target link, the search is concluded and the process proceeds to step 311. If not, it is determined that the search is not completed and the process proceeds to step 304. In step 304, candidate links are selected. That is, the terminal intersection of the reference link is checked from the link information data stored in the link information storage means 102 in FIG. These are extracted as candidate links. However, at this time, the right/left turn prohibition information data shown in FIG. 6 is checked, and the prohibited links from the reference links stored therein are not adopted as candidate links. Next, in step 305, the evaluation value of the reference link obtained from the link information data is added to the total evaluation value from the departure link to the reference link recorded in the search result data, thereby creating a new overall evaluation from the departure link to the candidate link. Calculate value. In step 306, the calculated new total evaluation value is compared with the total evaluation value recorded in the search result data, and if the new total evaluation value is smaller, the process proceeds to step 307; otherwise, the process proceeds to step 310. In steps 307 to 309, search result data is rewritten for candidate links. First, in step 307, the calculated new total evaluation value is recorded, then in step 308, the reference link is recorded as the previous link, and finally, in step 309, the candidate state flag is set to 1 for the candidate state. Next, in step 310, it is determined whether all the links connected to the reference link, excluding links that are prohibited from turning right or left, have been selected as candidate links. If they have been selected, the process returns to step 302 and the next reference link is selected. If not, the process returns to step 304 and the search is repeated using the remaining connection links as candidate links. If it is determined in step 303 that the search has ended, step 311
The route is reconstructed from the search result data.

FIG. 11 is a detailed flow diagram showing route reconfiguration. Hereinafter, step 3 in FIG. 9 according to FIG.
11 will be explained in detail. First, in step 501, the target link is set as the current link to be recorded. Next step 502
records the current link as part of the route. Further, in step 503, it is determined whether the current link is a departure link, and if the departure link has not been reached, in step 504, the previous link is read from the current link information in the search result data and becomes the current link, and the process from step 502 is continued. repeat. If the departure link is reached, the process of step 311 in the flowchart of FIG. 9 ends. In step 312, the route thus recorded is displayed on the CRT by the output means 104 of FIG. 1, superimposed on the road network.

As described above, according to this embodiment, right/left turn prohibition information is provided as link information, and a search is performed based on the link while preventing the search from expanding to links where entry is prohibited. By keeping the search results for each link, it is possible to accurately select a route from the departure point to the destination, taking into account the prohibition of right and left turns.

Next, a second embodiment of the present invention will be explained. A block diagram of a recommended route guidance device showing the second embodiment of the present invention is the same as a block diagram of a recommended route guidance device showing the first embodiment shown in FIG. However, it is assumed that the intersection configuration link information data in the link information storage means 102 records data on the direction of exiting from the intersection through the link (hereinafter referred to as the exit direction) as shown in FIG. .

The operation of the second embodiment of the recommended route guidance system configured as described above will be explained below with respect to its differences from the first embodiment. FIG. 12 is a flow diagram of a recommended route guidance device showing a second embodiment of the present invention.

12 differs from FIG. 9 in that the process of step 313 is performed between step 304 and step 305, and the content of the process of step 305. In step 313, an intersection evaluation value is calculated. FIG. 13 is a detailed flowchart showing a method for calculating an intersection evaluation value. Hereinafter, the process of step 313 will be explained in detail according to FIG. First, in step 601, the intersection approach direction of the reference link is determined from the intersection configuration link information data (FIG. 3) stored in the link information storage means 102 by identifying an approach link whose direction is opposite to that of the reference link, and from that link direction. Calculate the intersection approach direction of the reference link. Furthermore, step 602
Similarly, the intersection escape direction of the candidate link is read from the intersection configuration link information data. In step 603, the angle of change in the traveling direction at the intersection is calculated by subtracting the intersection entry direction from the intersection exit direction, and the process proceeds to step 604. In step 604, it is determined that the vehicle is traveling straight, and if the traveling direction change angle is within ±30 degrees with the direction of rotation to the left being positive, it is determined that the vehicle is traveling straight. If it is determined that the vehicle is going straight, the intersection evaluation value is determined to be α in step 608, and this process ends. Otherwise, a left turn is determined in step 605. If the traveling direction change angle is between 30 degrees and 135 degrees, it is determined that a left turn is to be made, and the intersection evaluation value is determined to be β in step 609, and this process ends. Otherwise, a right turn determination is made in step 606. If the traveling direction change angle is between -30 degrees and -135 degrees, it is determined that a right turn is to be made, and the intersection evaluation value is determined to be γ in step 610, and this process ends. Otherwise, it is determined that there has been a sudden change in direction, and the intersection evaluation value is determined to be δ in step 607, and the process of step 313 in the flowchart of FIG. 12 is ended. However, here, 0
≦α≦β≦γ≦δ. Next, in step 305, the evaluation value of the reference link obtained from the link information data and the intersection evaluation value calculated in step 313 are added to the total evaluation value of the reference link recorded in the search result data from the departure link. Calculate the new total evaluation value until reaching the candidate link.

As described above, according to the second embodiment, by determining the evaluation value at the intersection, adding it to the total evaluation value, and performing a search based on the link, for example, the travel time can be determined at the intersection. It is possible to accurately select the minimum travel time route that minimizes the evaluation value that varies due to left/right turns, etc.

Next, a third embodiment of the present invention will be described. The block diagram of the recommended route guidance device showing the third embodiment of the present invention is the same as the block diagram of the recommended route guidance device showing the first embodiment shown in FIG.

The operation of the recommended route guidance device of the third embodiment configured as described above will be explained below with respect to the differences from the first embodiment. FIG. 14 is a flow diagram of a recommended route guidance device showing a third embodiment of the present invention.

14, the difference from FIG. 9 is that the process of step 314 is performed between step 301 and step 302, and the process of step 3 is performed between step 305 and step 306.
15 and step 316 are performed. In step 314, a departure/destination link evaluation value is calculated.

FIG. 15 is a detailed flowchart showing the method for calculating the departure/destination link evaluation value, and FIGS. 16(a) and 16(b) show the relationship between two departure links in opposite directions and the departure point. 17(a) and 17(b) are diagrams showing the relationship between two destination links and a destination in opposite directions. below,
The process of step 314 will be described in detail according to FIG. first,
Calculate the evaluation value of the departure link. In step 701, as shown in FIGS. 16(a) and 16(b), a perpendicular line is drawn from the departure point to the departure link to find the point at which the departure link is entered (hereinafter referred to as the departure link entry point), and this is Use the above as the starting point for the search. Furthermore, step 70
In step 2, it is determined whether the departure link is one-way. This determines one-way traffic depending on whether the link numbers for both directions are recorded in the node information A in FIG. 5(a),
If it is a one-way street, in step 703, the departure link entry evaluation value, which is the evaluation value for turning left or right to enter the departure link, is set to x, and the process moves to step 706. Otherwise, in step 704, a link that will turn right and enter the departure link is identified from the positional relationship between the departure link and the departure point, and the departure link entry evaluation value for that link is determined as y.
shall be. Further, in step 705, a link that will turn left and enter the departure link is similarly specified, and the departure link entry evaluation value for that link is set to x. Furthermore, for all departure links, in step 706, the evaluation value from the departure link approach point to the end point intersection on the departure link is calculated from the ratio to the entire departure link, and in step 707, from the departure link approach point to the end point intersection on the departure link. The value obtained by adding the departure link entry evaluation value to the evaluation value of is calculated and stored as the evaluation value of the departure link itself. However, here it is assumed that 0≦x≦y. Next, the evaluation value of the target link is calculated in the same way. In step 708, FIG.
) and as shown in FIG. 17(b), a perpendicular line is drawn from the destination to the destination link to find a point from which to escape from the destination link (hereinafter referred to as a destination link escape point). Furthermore, in step 709, it is determined whether the target link is a one-way traffic or not, in the same manner as in step 702, and if it is one-way, the target link escape evaluation value is set to x in step 710, and the process moves to step 713. Otherwise, in step 711, a link that causes a right turn to escape from the target link is specified, and the target link escape evaluation value for that link is set to y. Further, in step 712, a link that allows escape from the target link by turning left is specified, and the target link escape evaluation value for that link is set as x. Furthermore, regarding all the objective links, in step 713, the evaluation value from the starting point intersection on the objective link to the objective link escape point is calculated from the ratio to the entire objective link, and in step 714, from the starting point intersection on the objective link to the objective link escape point. The evaluation value of the target link itself plus the target link escape evaluation value is calculated and stored as the target link's own evaluation value. This completes the process of step 314 in FIG.

Hereinafter, as for the starting link, using the evaluation value obtained as described above, the search is expanded by repeating the selection of the reference link and the selection of the candidate link in the same way as in the first embodiment. If a target link is selected as a candidate link, it is determined in step 315, and if it is a target link, in step 316, the evaluation value of the target link itself calculated in step 314 is added to the new evaluation value calculated in step 304. The new evaluation value is corrected. For links other than the target link, the recommended route was selected based on the total evaluation value up to the link (that is, up to the link start point), but by performing this process, the target link is A recommended route will be selected based on the total evaluation value up to the time of escape, and the search results will be saved.

As described above, according to the third embodiment, the evaluation values of the departure link and the destination link themselves determined by the positions of the departure point and the destination are calculated, and when the destination link is searched, the evaluation value is calculated. By determining the recommended route based on the total evaluation value up to the point, it is possible to select a recommended route that takes into account not only points on the link but also left and right turns between the starting point and the destination at any point.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the gist of the present invention. For example, in this embodiment, the information stored in the link information storage means is expressed as shown in FIG. All you have to do is stay there. In addition, the evaluation value at an intersection may be made variable by changing not only the angle but also the type of road.
It may also be an evaluation value for right/left turns that is variable depending on the shape of the road such as a T-junction. In addition, for example, if you select an intersection as your starting point, all links that exit from this intersection will be set as departure links, and similarly, if you select an intersection as your destination, all links that enter this intersection will be set as destination links. There may be two or more departure links and two or more destination links, depending on the departure point and destination set in . In addition, in this example, the search was expanded based on links, but
Even if one virtual node is provided for one link and a virtual network is assumed along the connection of the link and a conventional search based on nodes is used, it is possible to use the search based on links as in this example. Search can be realized. Although the output means is a CRT display, audio guidance may also be provided. Furthermore, in combination with the current position detection means, guidance may be provided by voice or display when approaching an intersection at which a right or left turn is to be made.

[0032]

As is clear from the above description, according to the recommended route guidance device of the present invention, according to the first means, information on at least one of the direction of a one-way street and the possible direction of travel at an intersection is stored. By using that information to widen the search based on links and retaining the search results for each link, even if there are regulations such as prohibiting left or right turns, if there is a passable route, the route will always be found. It can be derived.

According to the second method, the evaluation value when passing through an intersection is determined based on the angle of change in the direction of travel at the intersection, and the evaluation value is added to the evaluation target, and the search is expanded using links as a reference, thereby reducing the loss time of turning right or left. The purpose is to reliably select routes that take into account such factors as

[0034]Furthermore, in the departure link and destination link corresponding to the departure point and destination determined according to the third means, a departure link approach evaluation value is an evaluation value for entering the departure link from the respective positional relationships. By calculating the destination link exit evaluation value, which is the evaluation value for heading from the destination link to the destination, and adding it to the evaluation target, it is possible to make right/left turns between the departure point and the destination at any point, not just points on the link. You can search for recommended routes.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a recommended route guidance device showing a first embodiment of the present invention.

[Figure 2] Diagram showing an example of a road network

[Figure 3] Diagram showing an example of intersection configuration link information data in this road network

[Figure 4] Diagram showing an example of link information data in this road network

[Fig. 5] (a) is a diagram showing an example of node information data in this road network. (b) is a diagram showing another example of node information data in this road network.

[Figure 6] Diagram showing an example of right/left turn prohibition information data in this road network

[Figure 7] Diagram explaining the relationship between link numbers and node numbers in node information data

[Figure 8] Diagram showing an example of search result data

FIG. 9 is a flow diagram showing the first embodiment of the recommended route guidance device of the present invention.

FIG. 10: Detailed flow diagram showing reference link selection

FIG. 11: Detailed flow diagram showing route reconfiguration

FIG. 12 is a flow diagram showing a second embodiment of the recommended route guidance device of the present invention.

[Figure 13] Detailed flow diagram showing the calculation method of intersection evaluation value

FIG. 14 is a flow diagram showing a third embodiment of the recommended route guidance device of the present invention.

[Figure 15] Detailed flow diagram showing the departure and destination link evaluation value calculation method

FIG. 16 (a) is a diagram showing a state in which a left turn is made to enter the departure link from the departure point; (b) is a diagram showing a state in which a right turn is made to enter the departure link from the departure place.

[Figure 17] (a) is a diagram showing a state in which the person turns left, escapes from the destination link, and heads for the destination; (b) is a diagram showing a state in which the person turns right, escapes from the destination link, and heads toward the destination.

[Fig. 18] Representation diagram of the cross intersection of the first conventional example

[Figure 19
]Block diagram of a route search device according to a second embodiment

[Figure 20]
Diagram showing an example of a road network that is difficult to search using conventional technology

[Explanation of symbols]

101 Point setting means 102 Link information storage means 103 Link search means 104 Output means

Claims (8)

[Claims] Claim 1: A point setting means for setting a departure point and a destination, a link information storage means for storing information regarding links between intersections on a road, and a starting point and a destination set by the point setting means. Recommended route guidance comprising: a link search means for searching for a route to a destination using link connection information stored in a link information storage means; and an output means for outputting the route obtained by the link search means. Device. [Claim 2] A link search means determines one or more departure links and one or more destination links from a departure point and a destination, respectively;
The recommended route guidance device according to claim 1, which searches for a route between a departure link and a destination link. 3. The link information storage means stores information on at least one of the direction of a one-way street and the possible direction of travel at an intersection, and the link search means uses information on at least one of the one-way street and the possible direction of travel. The recommended route guidance device according to claim 1, wherein the recommended route guidance device searches for a route. 4. The recommended route guidance device according to claim 1, wherein the link search means searches for a route in which evaluation values corresponding to going straight, turning right, and turning left at an intersection are added to the evaluation target. 5. The recommended route guidance device according to claim 1, wherein the link search means searches for a route in which an evaluation value determined by the angle of the route when passing through an intersection is added to the evaluation target. 6. The recommended route guidance device according to claim 1, wherein the link search means searches for a route from any point on the link to any point on another link. [Claim 7] When the starting point is not on a road, the link searching means searches for a route in which an evaluation value corresponding to a turning direction is added to the evaluation target when proceeding with the search from the starting point via the search starting point on the link. The recommended route guidance device according to claim 1. [Claim 8] When the destination is not on a road, the link search means evaluates the evaluation value corresponding to the direction in which the search progresses to the search end point on the link, passes through the search end point, and turns toward the destination. The recommended route guidance device according to claim 1, which searches for the added route.