JP6905912B2 - Pathfinding device, pathfinding method, computer program - Google Patents

Description

The present invention relates to a technique for searching for a route.

In recent years, route guidance for automobiles and pedestrians has been realized using a moving body such as a car navigation system or a smartphone. In such route guidance, convenience is improved by seeking routes that users often take or routes that they have taken (hereinafter collectively referred to as "use routes") and providing guidance on the use routes. The technology to plan is known. For example, Patent Document 1 describes a technique of associating surrounding links with each position of a moving body that changes with time and connecting the associated links to obtain a usage route. Patent Document 2 describes a technique that uses the degree of correlation between the estimated position of a moving body and the attribute of a link in order to accurately obtain the position of the moving body when a plurality of roads are running in parallel. ..

Japanese Unexamined Patent Publication No. 2001-101563 Japanese Unexamined Patent Publication No. 10-141968

The information on the position of the moving body may deviate from the actual situation depending on the accuracy of the current position acquisition means (for example, GPS: Global Positioning System) mounted on the moving body. In such a case, the technique of Patent Document 1 has a problem that a divergence occurs between the calculated usage route and the actual usage route. Further, in Patent Document 2, no consideration is given to the calculation of the utilization route.

For this reason, it has been required to search for a usage route close to the actual usage route in a route search device that searches for a route that the user often takes or a route that the user has taken (usage route).

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following forms. A route search device, which is a route information storage unit that stores road network data including node information and link information connecting the nodes, information of the link, and an arbitrary departure point of a moving body in the past. Supplementary information that supplements the temporal position information of the moving body when moving from to an arbitrary destination, and a cost adjustment unit that reduces the link cost in the route information storage unit for a specific link obtained from the above. A route search unit that executes a route search process for searching a route from the departure point to the arrival point with reference to the route information storage unit after reducing the link cost, and the route search unit searched by the route search unit. The guide control unit for guiding the route from the departure point to the arrival point where the moving body has moved in the past by using the route is provided, and the supplementary information is the current position mounted on the moving body. It is the accuracy of the position information of the moving body acquired by the acquisition unit, and the cost adjustment unit has the accuracy of all the links including at least a part of the polygons whose accuracy is lower than a predetermined reference. A route search device that refers to information and extracts the link having information that affects the decrease in accuracy to make the specific link. In addition, the present invention can also be realized in the following forms.

(1) According to one embodiment of the present invention, a route search device is provided. This route search device supplements the route information storage unit that stores the road network data including the node information and the information of the link connecting the nodes, the information of the link, and the temporal position information of the moving body. For a specific link obtained from the supplementary information to be performed, the route search process is executed with reference to the cost adjustment unit for reducing the link cost in the route information storage unit and the route information storage unit after reducing the link cost. It is provided with a route search unit.
According to this form of route search device, the cost adjustment unit is selected in the route search process by reducing the link cost for a specific link obtained by using supplementary information that supplements the temporal position information of the moving body. Make it easier. As a result, according to the route search device of the present embodiment, it is possible to search for a usage route close to the actual usage route.

(2) In the route search device of the above-described embodiment, the supplementary information is the accuracy of the current position acquisition unit that acquires the position information, and the cost adjustment unit determines that the accuracy is lower than a predetermined reference. The link information may be referred to, and the link having information that affects the accuracy reduction may be extracted and used as the specific link.
According to the route search device of this form, when the accuracy of the current position acquisition unit (for example, GPS) represented by the supplementary information is lower than the predetermined standard, the cost adjustment unit causes the event to occur in the moving body. By presuming that it is the result of passing through the road (link) that causes the deterioration and reducing the link cost of the link having information (for example, tunnel) that affects the accuracy reduction, it can be easily selected in the route search process. ..

(3) In the route search device of the above-described embodiment, the supplementary information is information about the user of the moving body, and the cost adjustment unit refers to the information of the link and is related to the information about the user. The link having a high property may be extracted and used as the specific link.
According to this form of route search device, the cost adjustment unit estimates that the link is a path (link) that the user has passed through a link that is highly relevant to the information about the user, and reduces the link cost to search the route. It can be easily selected in the process.

(4) In the route search device of the above-described embodiment, the link included in the polygon having a predetermined shape generated from the position information over time is extracted and extracted with reference to the route information storage unit. For links other than the extracted link or the extracted link, a link limiting unit that limits the link selected in the route search process by updating the information of the link in the route information storage unit is further provided. The route search unit may execute the route search process with reference to the updated route information storage unit.
According to the route search device of this form, the link limiting unit limits the links selected in the route search process by updating the information of the links in the route information storage unit. Therefore, since it is sufficient for the route search unit to execute the normal route search process by referring to the route information storage unit updated by the link limiting unit, it is not necessary to perform any special processing, and the processing load in the route search unit. Can be reduced. Further, since it is sufficient for the link limiting portion to extract the link included in the polygon generated from the temporal position information of the moving body, the high-load "position-link association process" is not required. Further, the link limiting unit can distinguish the extracted link from other links by updating the information of the link in the route information storage unit. Therefore, for example, a new link only for the extracted link is newly added. The processing load can be reduced as compared with the case of generating and holding road network data. As a result, according to the route search device of the present embodiment, the processing load can be reduced and the increase in the time required for the processing can be suppressed.

(5) In the route search device of the above-described embodiment, the link limiting unit adds information to the effect that the route search process does not target the route search, or adds information to the information of the link regarding the other link. The link cost of the other link may be changed higher than the link cost of the extracted link.
According to this form of the route search device, the link limiting unit can limit the links selected in the route search process by distinguishing the links other than the extracted links from the extracted links. ..

The present invention can be realized in various aspects, for example, a route search device, a route guidance device, a method executed in an information processing device to realize the functions of each of these devices, and each of these devices. It can be realized in the form of a navigation system including, a computer program for realizing the functions of each of these devices and systems, a server device for distributing the computer program, a non-temporary storage medium for storing the computer program, and the like. can.

It is a figure which shows the schematic structure of the navigation system as one Embodiment of this invention. It is a figure explaining the operation of a navigation system. It is a sequence diagram which shows the procedure of the use route search processing. It is a figure explaining the use route search process steps S10-S14. It is a figure explaining the step S20, S22 of the use route search process. It is a figure explaining the use route search processing steps S24-S32. It is a figure explaining the utilization route search process considering the order of polygons. It is a figure explaining the utilization route search process considering the order of polygons. It is a figure explaining an example of the use route search process using the road network data of a plurality of layers. It is a figure explaining another example of the use route search process using the road network data of a plurality of layers. It is a figure explaining the polygon generation method. It is a figure explaining the deformation of a polygon. It is a figure which shows the schematic structure of the navigation system in 2nd Embodiment. It is a sequence diagram which shows the procedure of the use route search process in 2nd Embodiment. It is a figure explaining the utilization route search process in 2nd Embodiment. It is a figure explaining the use route search process using other supplementary information.

A. First Embodiment:
A-1. Navigation system configuration:
FIG. 1 is a diagram showing a schematic configuration of a navigation system as an embodiment of the present invention. The navigation system 1 is a system that searches for a route that a user often takes or has taken (hereinafter, also collectively referred to as a "use route") and provides guidance regarding the use route.

FIG. 2 is a diagram illustrating the operation of the navigation system. The navigation system 1 of the present embodiment extracts and extracts the link LK included in each polygon for the polygons P1 to P5 (FIG. 2: dot hatching) generated from the temporal position information of the moving body 20. By performing the route search process for the link LK, the usage route RT between the departure point S and the arrival point G of the moving body 20 is obtained, and guidance regarding the usage route RT is performed. In the following, the case where the user travels by car will be illustrated, but when the user uses other means of transportation (walking, bicycle, various public transportation, etc.) or a combination of multiple means of transportation is used. The case can be configured in the same manner.

Returning to FIG. 1, the navigation system 1 includes a server 10 that functions as a "route search device" and a mobile body 20. The server 10 is connected to the Internet INT by wire communication. The mobile body 20 is connected to the Internet INT by wireless communication via the communication carrier BS. The communication carrier BS includes a transmission / reception antenna, a radio base station, and an exchange. That is, the server 10 and the mobile 20 can communicate with each other via the Internet INT.

The server 10 includes a CPU 110, a storage unit 120, a communication unit 130, and a ROM / RAM 140, and each unit is connected to each other by a bus (not shown).

The CPU 110 controls each part of the server 10 by expanding the computer program stored in the ROM 140 into the RAM 140 and executing the program. The CPU 110 also functions as an acquisition unit 112, a link limiting unit 114, a route search unit 116, and a guidance control unit 118. The acquisition unit 112, the link limiting unit 114, and the route search unit 116 cooperate to execute the use route search process described later. The usage route search process is a process for finding a route that a user often takes or a route that the user has taken (usage route). The guidance control unit 118 causes the mobile body 20 to guide the information regarding the usage route obtained in the usage route search process.

The storage unit 120 is composed of a hard disk, a flash memory, a memory card, and the like. In the following description, the database is also simply referred to as "DB". The storage unit 120 includes a map DB 122 and a route DB 124. The map DB 122 is a database that stores data representing a map image. The data representing the map image includes information necessary for displaying the map, such as topography, buildings, and road shapes.

The route DB 124 is a database in which road network data is stored. The road network data includes node information related to "nodes" representing the positions of intersections and landmarks such as stations, and link information related to "links" representing roads connecting the nodes. The road network data is used when the route search unit 116 searches for a route. The node information includes node position information, node type, node name, other node information, and the like. The link information includes the link cost for each means of transportation (the average travel time of the road represented by the link), the type of the link, the name of the link, the state of the link, and other information on the link. The route DB 124 functions as a "route information storage unit", and the link information functions as "link information".

The communication unit 130 controls communication with other devices via a communication interface (not shown). Other devices may include a mobile body 20, another server (not shown), and the like.

The mobile body 20 includes a CPU 210, a storage unit 220, a communication unit 230, a ROM / RAM 240, an input / output unit 250, and a current position acquisition unit 260, and each unit is connected to each other by a bus (not shown). ing.

The CPU 210 controls each part of the moving body 20 by expanding and executing a computer program stored in the ROM 240 in the RAM 240, and also functions as a polygon generation unit 212 and a guide unit 214. The polygon generation unit 212 cooperates with the server 10 to execute the usage route search process described later. The guide unit 214 outputs information regarding the use route obtained in the use route search process from the input / output unit 250.

The storage unit 220 is composed of a hard disk, a flash memory, a memory card, and the like. The communication unit 230 controls communication with another device such as the server 10 via a communication interface (not shown). The input / output unit 250 is various interfaces used for inputting / outputting information between the mobile body 20 and the user. As the input / output unit 250, for example, a touch panel as an input unit, an operation button, a microphone, a touch panel as an output unit, a liquid crystal panel, a speaker, an LED (Light Emitting Diode) indicator, and the like can be adopted. The current position acquisition unit 260 receives radio waves transmitted from artificial satellites constituting a GPS (Global Positioning System) and acquires position information (latitude and longitude) representing the current position of the moving body 20. ..

A-2. Usage route search processing:
FIG. 3 is a sequence diagram showing the procedure of the usage route search process. The usage route search process is a process of finding a route that the user often passes through or a route that the user has taken (usage route), and can be executed at an arbitrary timing. For example, the usage route search process may be always executed when the use of the current position acquisition unit 260 in a predetermined application mounted on the mobile body 20 is enabled.

FIG. 4 is a diagram illustrating steps S10 to S14 of the usage route search process. In step S10 of FIG. 3, the current position acquisition unit 260 of the moving body 20 acquires the time-dependent position information of the moving body 20 from the departure place to the arrival place. Here, for example, the current position acquisition unit 260 repeatedly acquires the position information at an arbitrary interval (for example, 1 second). The current position acquisition unit 260 can distinguish the departure point S, each position Li1 to Li5, and the arrival point G during the movement of the moving body 20 by using, for example, the amount of change of the repeatedly acquired position information per unit time (FIG. 4).

In step S12, the polygon generation unit 212 of the moving body 20 generates polygons from the position information (temporary position information) acquired repeatedly. The polygon generation unit 212 can generate polygons by any method, and for example, as shown in FIG. 4, can generate rectangular polygons P1 to P5 centered on each position Li1 to Li5 during movement. As shown in FIG. 4, for example, the polygon generation unit 212 may determine the aspect ratio of the polygons P1 to P5 by using the amount of change per unit time for each latitude or longitude. The polygon generation unit 212 may change the size of the polygons P1 to P5 according to the GPS accuracy information (details will be described later) indicating the degree of precision of the position information. For example, when the GPS accuracy information is higher than a predetermined reference, the polygon generation unit 212 can reduce the size of the polygon by considering that the user has a high probability of passing around the position represented by the position information. Further, when the GPS accuracy information is lower than the predetermined reference, the polygon generation unit 212 can increase the size of the polygon by considering that the probability that the user has passed around the position represented by the position information is low. The generated plurality of polygons P1 to P5 may have partially or wholly overlapping ranges.

In step S14, the polygon generation unit 212 of the moving body 20 transmits information about each polygon (hereinafter, also referred to as “polygon information”) to the server 10 for all the generated polygons. The polygon information includes position coordinate information that defines the shape of the polygon and the order of the polygons. As the position coordinate information that defines the shape of the polygon, any information can be used as long as the shape (including the size) of the polygon can be specified. In the present embodiment, since it is a rectangular polygon, the position information of the start point and the position information of the end point, that is, the position information of two diagonal points of the rectangle can be used. Instead of the position information of two diagonal points, a combination of position information of each corner of the rectangle or a combination of position information of a sequence of points along the edge of the rectangle may be used. The order of polygons is information indicating the number of polygons generated from the starting point S. In the case of the polygon P1 (dot hatching) shown in FIG. 4, the polygon information includes the position information G11 of the starting point, the position information G12 of the ending point, and the order "1" of the polygons. The order of the polygons in the polygon information can be omitted, and the polygon information may include other information (for example, position information Li1 to Li5 of the center point).

FIG. 5 is a diagram illustrating steps S20 and S22 of the usage route search process. In step S20 of FIG. 3, the acquisition unit 112 of the server 10 acquires polygon information from the moving body 20. Next, the link limiting unit 114 of the server 10 refers to the acquired polygon information and the route DB 124, and extracts each link passing through each polygon. When the route DB 124 includes a plurality of layers of road network data as in the modifications a4 and 5 described later, the link limiting unit 114 can extract a link using an arbitrary layer, but the extracted link is used. From the viewpoint of ease of connecting the routes, it is preferable to extract the link using a layer having a large amount of information as compared with the multi-layer.

Step S20 will be described by exemplifying polygons Pn (FIG. 5: dot hatching) of order n. The link limiting unit 114 refers to the link information of the route DB 124, and refers to a link in which at least a part thereof is included in the polygon Pn (FIG. 5: links L11, 12, 21 to 23, 31 to 3, 41, 42, 51 to 51 53, 61-65) are extracted. The link limiting unit 114 performs this link extraction for all the polygons included in the acquired polygon information.

In step S22, the link limiting unit 114 of the server 10 sets the link status of all the links (hereinafter, also referred to as "other links") other than the links extracted in step S20 to "closed" for all the link information of the route DB 124. Update to. For example, in the case of the polygon Pn shown in FIG. 5, the link state of the link information is updated to "closed" for each link marked with a cross.

FIG. 6 is a diagram illustrating steps S24 to S32 of the usage route search process. In step S24 of FIG. 3, the route search unit 116 of the server 10 uses the position information of the departure place S and the position information of the arrival place G to search for a route from the departure place S to the arrival place G. Here, the route search unit 116 may execute a normal route search process using the updated route DB 124 in step S22. In the updated route DB 124, the link information is changed to "closed" for all links (other links) not included in each polygon P1 to P5 from the departure place S to the arrival place G (FIG. 6). : Cross mark). Also, in normal route search processing, links whose link information is "closed" are excluded from selection. Therefore, the route search unit 116 can obtain a route RT in which only the links extracted by the link limiting unit 114 are selected by simply executing the normal route search process with reference to the updated route DB 124. (Fig. 6). In other words, the route RT is a route obtained by limiting the links selected in the route search process to the links extracted by the link limiting unit 114.

In step S20, links including at least a part of the polygons P1 to P5 are extracted, and in steps S22 and S24, the links selected in the route search process are limited to the extracted links. As a result, as shown in FIG. 6, a part of the route RT obtained as a result of the route search process may protrude from each of the polygons P1 to P5.

The route search process can be performed based on, for example, a well-known Dijkstra method, and arbitrary conditions may be added. Arbitrary conditions are provided by, for example, priority conditions for exploration (distance priority, time priority, road width priority, free road priority, toll road priority), VICS (Vehicle Information and Communication System, VICS is a registered trademark). Whether or not to consider various information to be provided can be adopted. Arbitrary conditions may be preset by the user or preset in the server 10.

In step S26, the guidance control unit 118 of the server 10 generates guidance information using the search result (route RT) obtained in step S24. The guidance control unit 118 can generate various guidance information, for example, to output to the moving body 20 the estimated arrival time when passing through the route RT with the arrival point G as the destination and the traffic-related information on the route RT. Guidance information can be generated. The traffic-related information may include congestion information and regulatory information of each link included in the route RT, disaster information and weather information in each area through which the route RT passes. Note that step S26 may be omitted.

In step S30, the guidance control unit 118 of the server 10 transmits the guidance information generated in step S26 to the mobile body 20. If step S26 is omitted, the guidance control unit 118 in step S30 transmits the search result (route RT) obtained in step S24 to the moving body 20.

In step S32, the guide unit 214 of the mobile body 20 outputs the guide information acquired from the server 10 to the input / output unit 250 at an appropriate timing. As a result, the user of the navigation system 1 (the user of the mobile body 20) can acquire various information about the route that is often taken and the route that has been taken (the route of use), which is convenient for the user. Can be improved. In addition, in FIG. 3, only the processing for the combination of one departure place S and the arrival place G is illustrated. However, similar processing may be executed serially or in parallel for a plurality of departure points S and arrival points G (plural use routes). In this case, the guidance information output in step S32 can be the guidance information regarding the current usage route.

As described above, according to the server 10 (route search device) of the above embodiment, the link limiting unit 114 updates the link information in the route DB 124 (route information storage unit) to perform the route search process (FIG. 3: Limit the links selected in step S24). Therefore, since it is sufficient for the route search unit 116 to execute the normal route search process with reference to the route DB 124 updated by the link limiting unit 114, it is not necessary to perform any special process, and the process in the route search unit 116 The load can be reduced. Further, since it is sufficient for the link limiting unit 114 to extract the links included in the polygons P1 to P5 generated from the temporal position information of the moving body 20 (FIG. 3: step S20), the high-load "position and link" is sufficient. Does not require "association process with". Further, the link limiting unit 114 can distinguish the extracted link from another link by updating the link information in the route DB 124 (FIG. 3: step S22), so that the extracted link is extracted separately, for example. The processing load can be reduced as compared with the case where new road network data of only the links are generated and retained. As a result, according to the server 10 of the present embodiment, it is possible to reduce the processing load and suppress an increase in the time required for processing.

A-3. Transformation of usage route search processing:
A modification of the usage route search process will be described. These modifications may be applied alone or in combination to the above-mentioned utilization route search process.

(A1) Modification of link information update (other links):
In step S22 of FIG. 3, the link limiting unit 114 of the server 10 arbitrarily sets the link information about other links to information other than "closed" so that the link is not selected in the route search process. You may update to the information of. For example, when the link information includes the "flag to be excluded from the search target in the route search process", the link limiting unit 114 indicates that the link is not the search target from "0" indicating that the flag is the search target. It may be changed to "1" shown. In this way, other links will not be selected in the normal route search process that refers to the flag.

Further, for example, the link limiting unit 114 may change the link cost included in the link information to be higher than the value stored in advance (for example, 10 times, 100 times, etc.). In this way, in the updated route DB 124, the link cost of the other link becomes higher than the link cost of the link extracted in step S20. In the normal route search process, a link having a smaller route RT cost is selected. Therefore, by changing the link cost to a higher value, the link is inevitably not selected.

In this way, the link limiting unit 114 can limit the links selected in the route search process by distinguishing "other links" other than the extracted links from the extracted links.

(A2) Modification of link information update (extracted link):
In step S22 of FIG. 3, the link limiting unit 114 of the server 10 targets the link information of the extracted link instead of other links, and arbitrary information such that the link is selected in the route search process. May be updated to. For example, when the link information includes a "flag to be searched in the route search process", the link limiting unit 114 indicates that the flag is a search target from "0" indicating that the flag is not a search target. It may be changed to "1". In this way, the extracted link is selected in the normal route search process with reference to the flag.

Further, for example, the link limiting unit 114 may change the link cost included in the link information to be lower than the value stored in advance (for example, 1/10, 1/100, etc.). In this way, in the updated route DB 124, the link cost of the extracted link is lower than the link cost of the other links. In the normal route search process, a link having a smaller route RT cost is selected. Therefore, by changing the link cost to a lower value, the link is inevitably selected.

In this way, the link limiting unit 114 can limit the links selected in the route search process by distinguishing the extracted links from other links.

(A3) Deformation considering the order of polygons:
7 and 8 are diagrams for explaining the utilization route search process in consideration of the order of polygons. In the Dijkstra method described above, cost-oriented route search processing is performed. Therefore, when the polygons P1 to P5 which are connected so as to be greatly curved as shown in FIG. 7 and the polygons P1 to P9 which are connected in a circle as shown in FIG. 8 are transmitted from the moving body 20, the cost is smaller. Path RT1 (FIG. 7, FIG. 8: broken line) may be selected. Such a route RT1 is a route that does not pass through all the polygons acquired from the moving body 20, and may deviate from the actual usage route. In this modification, the occurrence of such an event is suppressed.

Specifically, in step S22 of FIG. 3, the link limiting unit 114 of the server 10 extracts each link as "other link information" of the link information of the route DB 124 for the link extracted in step S20. Memorize the order of the original polygons. This is additionally performed in addition to the update of the link information described in FIG. 3 and the modifications a1 and 2. Further, in step S24, the route search unit 116 refers to the updated route DB 124 during the route search process, and according to the order of the polygons stored in the information of other links, the order of the polygons is not omitted and the order is ascending. Select the link so that it is continuous with.

In this way, the route search unit 116 selects the links according to the order of the polygons added to the link information in the route DB 124. Therefore, in the route search process in step S24, it is possible to select a link that follows (follows) the change in the position of the moving body 20 over time, and the usage route RT2 (FIG. 7, FIG. 7, which is close to the actual usage route). FIG. 8: Solid line) can be searched. In addition, this modification is also useful when, for example, the departure place S and the arrival place G are the same place (when starting from home, going around the vicinity, and returning to home, etc.).

(A4) Modification using multi-layer road network data (1):
FIG. 9 is a diagram illustrating an example of a usage route search process using a plurality of layers of road network data. In this modification, the route DB 124 stores a plurality of layers of road network data having different amounts of information. For example, as shown in FIG. 9, a case where two layers of road network data of level 0 (upper) and level 1 (lower) are stored is illustrated. In the level 0 road network data, both links L1 and L2 representing large roads such as national roads and highways and links L3 and L4 representing small roads such as municipal roads are stored. On the other hand, in the level 1 road network data, only links L1 and L2 representing large roads such as national roads and highways are stored. That is, the amount of information of the road network data at levels 0 and 1 is different, and the amount of information at level 1 is smaller than that at level 0. Note that in FIG. 9, the polygon between the polygon P5 and the polygon P11 is not shown.

In this modification, in step S20 of FIG. 3, the following is performed instead of the above-described processing.
The link limiting unit 114 is at level 0 of the route DB 124, which has a large amount of information for polygons P1 to P3 around the departure point S and polygons P13 to P15 (FIG. 9: dot hatching) around the arrival point G. Links are extracted using road network data.
-The link limiting unit 114 provides level 1 road network data of the route DB 124, which has a small amount of information, to other polygons P4 to P12 (FIG. 9: diagonal hatching) that are not around the departure point S and the arrival point G. Use to extract links.
As a result, in the route search process of step S24, in the vicinity of the departure point S and the arrival point G (dot hatching area), a link targeting a small road such as a municipal road based on level 0 is selected, and the departure point S is selected. Between the destination G and the destination G (diagonal hatched area), a link for a large road such as a national highway or a highway based on level 1 is selected.

Note that this transformation is executed only when the distance between the departure point S and the arrival point G is long, in other words, when the distance between the departure point S and the arrival point G is equal to or greater than a predetermined threshold value. You may. Generally, when the distance between the departure point S and the arrival point G is long, there is a high probability that a large road such as a national highway or an expressway will be used, so that this modification becomes more effective. In this modification, the case where the route DB 124 has a two-layer structure of levels 0 and 1 is illustrated, but the route DB 124 may be divided into a plurality of layers of three or more layers. In this case, the link limiting unit 114 is any layer as long as "the amount of information of the layer used for link extraction of the polygon including the departure place S and the arrival place G> the amount of information of the layer used for link extraction of other polygons". May be used. Further, the link limiting unit 114 may use a layer having a large amount of information only for either the departure place S or the arrival place G.

In this way, the link limiting unit 114 refers to polygons P4 to P12 (that is, polygons located at an intermediate point between the departure point S and the arrival point G) that are not around the departure point S and the arrival point G. Since the link is extracted by referring to the road network data of the layer with a small amount of information, the processing load required for link extraction can be reduced.

(A5) Transformation using multi-layer road network data (2):
FIG. 10 is a diagram illustrating another example of the use route search process using the road network data of a plurality of layers. In this modification, similarly to the modification a4, road network data of a plurality of layers (for example, two layers of levels 0 and 1) having different amounts of information are stored in the route DB 124.

In this modification, the link limiting unit 114 further excludes the links corresponding to both of the following conditions 1 and 2 from the links extracted in step S20 after executing step S20 in FIG.
-Condition 1: A link included in level 1 road network data with a small amount of information in the route DB 124.
Condition 2: A link in which at least one of the nodes at both ends of the link is located outside the plurality of polygons P1 to P5 acquired in step S20.
As a result, from the links extracted in step S20, the links L1 and L2 representing large roads such as national roads and highways (condition 1), and at least one node N22 is located outside the polygons P1 to P5. L2 (condition 2) is excluded. The link L2 excluded here is treated as "another link" and is excluded from the selection in the route search process.

In this modification as well, the case where the route DB 124 has a two-layer structure of levels 0 and 1 is illustrated, but the route DB 124 may be divided into a plurality of layers of three or more layers. In this case, the link limiting unit 114 may use any layer as long as "the amount of information of the layer used for link extraction in step S20> the amount of information of the layer used in condition 1".

Road network data of a layer (for example, level 1 in FIG. 10) having less information than other layers (for example, level 0 in FIG. 10) generally includes links representing large roads such as highways and national roads. It contains information and does not include information on links that represent small roads, such as municipal roads. In this way, when at least one of the nodes N11, 12, N21, and 22 at both ends of the links L1 and L2 representing the large road is outside the plurality of polygons P1 to P5, the link limiting unit 114, in other words, If at least one of the ends of the large road deviates from the temporal change in position of the moving body 20, it is estimated that the link is not the road that the moving body 20 has passed through, and the link is extracted in step S20. It can be pre-excluded from the link. As a result, in the route search process in step S24, it is possible to search for a usage route that is close to the actual usage route. This is useful for guiding the correct usage route, for example, when the expressway and the national highway run side by side halfway.

(A6) Modification of polygon generation method:
FIG. 11 is a diagram illustrating a polygon generation method. In step S12 of FIG. 3, the polygon generation unit 212 of the moving body 20 may generate a rectangular polygon having the position information at a certain time t and the position information at the next time t + 1 diagonally. For example, when the position information at time t is G1, the position information at time t + 1 is G2, and the position information at time t + 2 is G3, the polygon generation unit 212 has polygons P1 and G2 with the G1 point and the G2 point diagonal to each other. A polygon P2 with a point and a G3 point diagonally can be generated.

In this way, the polygon generation unit 212 can easily generate polygons from the temporal position information of the moving body 20. Further, since the generated polygon has a rectangular shape with two points (position information at time t and position information at time t + 1) diagonally, it is possible to simplify the calculation in the polygon generation unit 212 and the link limiting unit 114. can. The polygon generation unit 212 may be provided in the server 10. Even in this case, according to this modification, polygons can be easily generated only by acquiring position information over time from the moving body 20.

The number of polygons generated by the polygon generation unit 212 does not have to be a plurality (or one). Further, the polygon generated by the polygon generation unit 212 may have an arbitrary shape, and may have a shape other than the rectangular shape. For example, it may be circular or polygonal. In the case of a circle, the position coordinate information that defines the shape of the polygon can be defined by a combination of the position information of the center point and the radius, a sequence of points along the edge of the circle, and the like. In the case of a polygon, the position coordinate information that defines the shape of the polygon includes the combination of the position information of each corner, the combination of the position information of the point sequence along the edge of the polygon, and the position information of the center point of the polygon. It can be defined by the combination of distances to the corners.

(A7) Transformation of polygon change:
FIG. 12 is a diagram illustrating deformation of polygons. In step S20 of FIG. 3, the link limiting portion 114 of the server 10 changes the size of each polygon P2, P3 (FIG. 12: broken line) used for extracting the link, and the changed polygons P2a, P3a (FIG. 12 :). The link contained in the alternate long and short dash line) may be extracted. The link limiting unit 114 may change the size of the polygon according to, for example, the following rules 1 to 4. The change width PL of the size may be uniformly determined, or may be dynamically determined according to the fluctuation width such as the number, density, and magnitude in Rules 1 to 4.

-Rule 1: Temporarily extract the links included in the polygon, and reduce or enlarge the polygon according to the number of temporarily extracted links.
-Rule 2: Temporarily extract the links included in the polygon, obtain the "link density in the polygon" from the number of temporarily extracted links and the polygon, and reduce or enlarge the polygon according to the link density.
Rule 3: The polygon is reduced or enlarged according to the attribute of the place where the polygon is located (the amount of information in the route DB 124 or the map DB 122).
-Rule 4: The polygon is reduced or enlarged according to the size of the polygon.

In this way, the link limiting unit 114 can change the size of the polygon used for extracting the link. Therefore, for example, it is possible to suppress the occurrence of a huge number of links being extracted due to the polygon being too large and the number of links being extracted being extracted due to the polygon being too small. be able to.

B. Second embodiment:
In the second embodiment of the present invention, the configuration for searching for a usage route closer to the actual usage route in the navigation system 1 of the first embodiment will be described. Hereinafter, only the portion having a configuration and operation different from that of the first embodiment will be described. In the figure, the same components as those of the first embodiment are designated by the same reference numerals as those of the first embodiment described above, and detailed description thereof will be omitted.

B-1. Navigation system configuration:
FIG. 13 is a diagram showing a schematic configuration of the navigation system according to the second embodiment. The navigation system 1a includes a server 10a and a mobile body 20a. The server 10a further includes a cost adjustment unit 119 in addition to the units described in the first embodiment. The cost adjustment unit 119 cooperates with the acquisition unit 112, the link limiting unit 114, and the route search unit 116 to execute the usage route search process according to the second embodiment. The moving body 20a includes a polygon generation unit 212a instead of the polygon generation unit 212 described in the first embodiment. The polygon generation unit 212a cooperates with the server 10a to execute the usage route search process in the second embodiment.

B-2. Usage route search processing:
FIG. 14 is a sequence diagram showing a procedure of the usage route search process in the second embodiment. The difference from the first embodiment (FIG. 3) is that S50 is provided instead of step S14, and step S52 is executed between steps S22 and S24.

In step S50, the polygon generation unit 212a of the moving body 20a transmits polygon information to the server 10a for all the polygons generated in step S12. Here, the polygon information of the second embodiment includes GPS accuracy information in addition to the position information of the starting point, the position information of the ending point, and the order of the polygons. The GPS accuracy information is information acquired together with the current position acquisition unit 260 when acquiring the position information, and is information indicating the degree of precision of the position information which is the source of polygon generation. As the GPS accuracy information, for example, radio wave strength, information from which the position information is derived, and the like are used. The GPS accuracy information functions as "supplementary information".

In step S52, the cost adjustment unit 119 of the server 10a refers to the polygon information acquired in step S20, determines whether or not the GPS accuracy information is lower than the predetermined reference for each polygon, and the polygon lower than the predetermined reference. The following processes 1 and 2 are executed for. The predetermined reference can be arbitrarily determined according to how the GPS accuracy information is represented. For example, when the GPS accuracy information is the radio field intensity, some threshold value can be used as a predetermined reference.

-Process 1: Obtain a "specific link" that is presumed to have affected the deterioration of GPS accuracy. For example, the cost adjustment unit 119 can refer to the link information of the route DB 124, extract a link having information matching a predetermined pattern, and make it a specific link. The predetermined pattern can be arbitrarily determined, for example, link type = tunnel, link type = under-elevated link, link name = XX tunnel (X is an arbitrary character string, the same applies hereinafter).
-Process 2: For a specific link, the link cost of the link information of the route DB 124 is reduced. The link cost may be reduced by a constant value, a constant ratio (for example, 1/10, 1/100, etc.), a variable value, or a variable ratio (for example, 1/10 to 1/100). Any ratio of) may be used.

FIG. 15 is a diagram for explaining the usage route search process in the second embodiment. For example, consider the case where the server 10a acquires the illustrated polygons P1 to P4 (FIG. 15: dot hatching). Here, it is assumed that the GPS accuracy information of the polygon P2 is lower than the predetermined reference in step S52, and the GPS accuracy information of the polygons P1, 3 and 4 is higher than the predetermined reference in step S52. In this case, in the utilization route search process (FIG. 14), in step S52, a specific link presumed to have affected the decrease in GPS accuracy of the polygon P2 is required. For example, when the link type of the link L1 = tunnel (TN, diagonal hatching), the route DB 124 is updated in step S52, and the link cost of the link L1 is reduced. As a result of executing the route search process in step S24 in that state, the route RT2 (solid line) is selected instead of the route RT1 (broken line).

As described above, according to the server 10a (route search device) of the second embodiment, the cost adjustment unit 119 has the accuracy of the current position acquisition unit 260 (for example, GPS) represented by the GPS accuracy information (supplementary information). When it is lower than the predetermined standard, it is estimated that the event (decrease in accuracy) occurs as a result of the moving body 20 passing through the road (link) that causes the decrease in accuracy, which affects the decrease in accuracy. By reducing the link cost of the link having the information (for example, tunnel, under the elevated, etc.), the link can be easily selected in the route search process in step S24. As a result, according to the server 10a of the present embodiment, it is possible to search for a usage route close to the actual usage route.

B-3. Transformation of usage route search processing:
In the utilization route search process of the second embodiment, various modifications described in the modifications a1 to a7 of the first embodiment are possible. Further, in the usage route search process of the second embodiment, the modification described below is also possible. These modifications may be applied alone or in combination to the above-mentioned utilization route search process.

(B1) Deformation that omits polygons:
In the navigation system 1a, the usage route may be obtained from the position information and the supplementary information (for example, GPS accuracy information) without using polygons. In this case, the polygon generation in step S12, the link extraction using the polygons in step S20, and the update process in step S22 may be omitted. Further, in step S50, position information is used instead of the start point and the end point of the polygon.

In this way, the cost adjustment unit 119 reduces the link cost for the specific link obtained by using the supplementary information (GPS accuracy information) that supplements the temporal position information of the moving body 20a, thereby performing the link. Make it easier to select in the route search process. As a result, it is possible to search for a usage route that is close to the actual usage route.

(B2) Transformation of supplementary information:
FIG. 16 is a diagram illustrating a usage route search process using other supplementary information. The difference from the second embodiment (FIG. 14) is that S60 is provided instead of step S50, and S62 is provided instead of step S52.

Regarding step S60, the polygon information of this modification includes user information instead of GPS accuracy information. The user information is information about the user of the mobile body 20a, and various information that can be used to estimate the user's usage route can be adopted. For example, user information includes names and location information of facilities that users often go to, information for estimating facilities that users often go to (for example, occupation, illness, food preference, family structure, etc.), and users. The means of transportation (vehicles such as walking, bicycles, wheelchairs, automobiles, etc.), the age and gender of the user, and combinations thereof can be adopted. The user information functions as "supplementary information".

In step S62, the cost adjustment unit 119 of the server 10a collates the user information acquired in step S20 with the link information of the route DB 124, extracts a link having highly relevant link information to the user information, and extracts the link. Let's call it a "specific link". At this time, the server 10a may also use a facility DB (not shown). After that, the cost adjustment unit 119 reduces the link cost of the link information of the route DB 124 for a specific link.

As a result, for example, when the user information is "facility that the user often visits = XX hospital", the cost adjustment unit 119 refers to the facility DB and the route DB 124, and specifies a link close to the "XX hospital". Make it a link. For example, when the user information is "user's means of transportation = walking", the cost adjustment unit 119 refers to the route DB 124 and sets the link corresponding to the sidewalk as a specific link. For example, when the user information is "user's means of transportation = wheelchair", the cost adjustment unit 119 refers to the route DB 124 and can pass by a wheelchair from the width of the link stored in the other link information. Ask for a link and make it a specific link.

In this way, the cost adjustment unit 119 estimates that the link that is highly relevant to the information about the user is the path (link) that the user has passed through, and selects it in the route search process by reducing the link cost. Can be easily done.

C. Modification example:
In the above embodiment, a part of the configuration realized by the hardware may be replaced with software, and conversely, a part of the configuration realized by the software may be replaced with the hardware. good. In addition, the following modifications are possible.

-Modification example 1:
In the above embodiment, the configuration of the navigation system 1 including the server 10 (route search device) is illustrated. However, the configuration of the navigation system 1 is just an example, and any aspect can be adopted. For example, the server 10 may be realized by a plurality of server devices, and a plurality of mobile bodies 20 may be connected. Various devices such as smartphones, personal computers, navigation-dedicated devices, game machines, and wearable devices can be adopted as the mobile body 20. For example, in the navigation system 1, the case where the latitude / longitude coordinate system is used as the position information is illustrated, but another coordinate system (for example, the XY coordinate system) may be used as the position information.

-Modification example 2:
In the above embodiment, the configuration of the server 10 (route search device) is illustrated. However, the configuration of the server 10 is just an example, and any aspect can be adopted. For example, a part of the component can be omitted or changed, or a component can be added. For example, each of the above-mentioned functions may be realized by the cooperation of a plurality of servers, and at least a part of each of the above-mentioned DBs may be stored in the internal / external storage device of another device, for example. It may be built on the cloud. The configuration of each DB described above can be arbitrarily changed, and items can be added / deleted / changed, and the data storage format can be changed. Changes in the data storage format include table division / change and changes in how to have relationships.

-Modification example 3:
In the above embodiment, the usage route search process (FIGS. 3 and 14) has been described with an example of the process procedure. However, these processing procedures can be changed in various ways, and the processing contents in each step may be added / omitted / changed, or the execution order of the steps (procedures) may be changed.

(1) In the usage route search process of the above embodiment, the server 10 generates guidance information and transmits it to the mobile body 20 (steps S26 and S30). However, the server 10 may transmit the search result (information on the searched route) to another server and generate guidance information on the other server. Further, the server 10 may transmit the search result to the mobile body 20 and generate and output the guidance information in the mobile body 20.

(2) The usage route search process of the above embodiment and the modification of the usage route search process described in the modifications a1 to a7, b1 and b2 may be used properly according to the user's setting and predetermined conditions. As the predetermined conditions, for example, the status of data maintenance in the route DB 124 of the server 10, the content of the polygon information received by the server 10 from the mobile body 20, the parameters received together with the polygon information, and the like can be adopted.

(3) In the usage route search process of the second embodiment, GPS accuracy information as supplementary information may be omitted. As described above, each polygon is generated by using the temporal position information of the moving body 20. Therefore, the polygon generated from the low-precision position information is generally larger than the polygon generated from the high-precision position information. Utilizing this property, the server 10a estimates the height of the GPS accuracy information using the statistical value of the size of each polygon acquired from the moving body 20, and even if the processing of the second embodiment is performed. good.

-Modification example 4:
The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations within a range not deviating from the gist thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the column of the outline of the invention may be used to solve some or all of the above-mentioned problems. , It is possible to replace or combine as appropriate to achieve some or all of the above effects. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

1 ... Navigation system 10, 10a ... Server (route search device)
20, 20a ... Mobile 110 ... CPU
112 ... Acquisition unit 114 ... Link limiting unit 116 ... Route search unit 118 ... Guidance control unit 119 ... Cost adjustment unit 120 ... Storage unit 130 ... Communication unit 140 ... ROM / RAM
210 ... CPU
212, 212a ... Polygon generation unit 214 ... Guide unit 220 ... Storage unit 230 ... Communication unit 240 ... ROM / RAM
250 ... Input / output unit 260 ... Current position acquisition unit

Claims (6)

It is a route search device
A route information storage unit that stores road network data including node information and information on links connecting the nodes, and
The specific link obtained from the information of the link, supplementary information supplementing the temporal position information of the moving body when the moving body has moved from an arbitrary starting point to an arbitrary arrival point in the past , and the above-mentioned A cost adjustment unit that reduces the link cost in the route information storage unit,
A route search unit that executes a route search process for searching a route from the departure point to the arrival point with reference to the route information storage unit after reducing the link cost.
Using the route searched by the route search unit, a guidance control unit that guides the route from the departure point to the arrival point where the moving body has moved in the past, and a guidance control unit.
Equipped with a,
The supplementary information is the accuracy of the position information of the moving body acquired by the current position acquisition unit mounted on the moving body.
The cost adjusting unit refers to the information of all the links including at least a part of the polygons for the polygons whose accuracy is lower than the predetermined reference, and extracts the links having the information affecting the accuracy reduction. above shall be the specific link, the route search device. The route search device according to claim 1.
The supplemental information includes further information about the user of the mobile,
The cost adjustment unit refers to the information of the link, extracts the link highly related to the information about the user, and sets the link as the specific link. The route search device according to claim 1 or 2, further comprising:
With reference to the route information storage unit, the link included in the polygon having a predetermined shape generated from the position information over time is extracted, and the extracted link or other than the extracted link is extracted. The link is further provided with a link limiting unit that limits the link selected in the route search process by updating the information of the link in the route information storage unit.
The route search unit is a route search device that executes the route search process with reference to the updated route information storage unit. The route search device according to claim 3.
The link limiting part, with respect to the information of the link about the other link,
In the route search process, information to the effect that the route search is not performed is added, or
A route search device that changes the link cost of the other link higher than the link cost of the extracted link. It ’s a way to find a route,
An information processing device including a route information storage unit that stores road network data including node information and link information connecting the nodes.
The specific link obtained from the information of the link, supplementary information supplementing the temporal position information of the moving body when the moving body has moved from an arbitrary starting point to an arbitrary arrival place in the past , and the above-mentioned The process of reducing the link cost in the route information storage unit,
A step of executing a route search process for searching for a route from the departure point to the arrival point with reference to the route information storage unit after reducing the link cost.
Using the route searched by the route search process, a step of guiding the route from the departure point to the arrival point where the moving body has moved in the past, and a step of guiding the route.
Equipped with a,
The supplementary information is the accuracy of the position information of the moving body acquired by the current position acquisition unit mounted on the moving body.
In the step of reducing the link cost, for a polygon whose accuracy is lower than a predetermined reference, the information of all the links including at least a part of the polygon is referred to, and the information having information affecting the accuracy reduction is obtained. wherein it shall be the specific link to extract the link method. It ’s a computer program,
An information processing device including a route information storage unit that stores road network data including node information and link information connecting the nodes.
The specific link obtained from the information of the link, supplementary information supplementing the temporal position information of the moving body when the moving body has moved from an arbitrary starting point to an arbitrary arrival point in the past , and the above-mentioned Steps to reduce the link cost in the route information storage unit,
A step of executing a route search process for searching for a route from the departure point to the arrival point with reference to the route information storage unit after reducing the link cost.
Using the route searched by the route search process, a step of guiding the route from the departure point to the arrival point where the moving body has moved in the past, and a step of guiding the route.
To run ,
The supplementary information is the accuracy of the position information of the moving body acquired by the current position acquisition unit mounted on the moving body.
In the step of reducing the link cost, for a polygon whose accuracy is lower than a predetermined reference, the information of all the links including at least a part of the polygon is referred to, and the information having information affecting the accuracy reduction is obtained. wherein it shall be the specific link, the computer program to extract the link.

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