JP2006125850A - Guidance route searching device and guidance route searching method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly search a U-turn route at the pass point as a guidance route. <P>SOLUTION: The guidance route searching device comprises: the determination means 42 for determining the capability of U-turn at the pass point or stop-off point; the setting means 42 does't set the condition for prior calculation along the road stored in the calculation requirement means 15 as the condition 46 of the cost calculation when judged by the determination means 42 that the U-turn is capable; the cost calculation means 44 calculates the cost of the searched route under the calculation condition 46 set by using each link and node stored in the information memory means 15; and the selection means 45 for selecting one route for the guidance route 48 from among a plurality of searched routes by comparing the cost of the plurality of routes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a guide route search device and a guide route search method.

  Patent Document 1 discloses a route guidance device. In this route guidance device, when the relay point is set as a stop point, the route search means includes a road portion connected to the relay point of the second route from the searched relay point to the destination point, and the relay point from the departure point. The angle formed with the road portion connected to the relay point of the first route to the road is calculated, and a large weight is given to the road portion that is small and makes a U-turn around the relay point and returns backward. Among a plurality of searched road portions, a road portion having a small weight is determined as a road portion forming the recommended route of the second route. According to the determined recommended route of the second route, the route guidance means displays the recommended route and the position of the vehicle on the display screen of the output means, and performs route guidance.

JP-A-8-320237 (abstract, claims, detailed description of the invention, etc.)

  As disclosed in the conventional route guidance device described in Patent Document 1, the conventional guidance route search device searches for a guidance route that goes straight along a road at a passing point such as a stopover or a stop. As a result, there is no need to search for a U-turn route at the passing point.

  However, it is not always preferable to restrict the U-turn route so as not to be searched for at the passing point in this way in light of actual traffic conditions. For example, when shopping with a vehicle parked at a department store's underground parking lot set as a passing point, return to the direction of traveling toward that department store's underground parking lot and go to the next stop or destination. It may be desirable to proceed.

  An object of the present invention is to provide a guidance route search apparatus and a guidance route search method that can appropriately make a U-turn route at a passing point as a guide route.

  When searching for a route in a section from a passing point to a next passing point or a destination in a search for a guiding route from a starting point via a passing point to a destination, In a guidance route search device that executes straight road priority control that gives priority to a link and / or a node ahead in the direction of travel to a passage point in a route to a passage point, it is possible to make a U-turn at the passage point. Judgment means for judging whether or not there exists, cost information storage means for storing cost information of links and / or nodes selected as routes, and judgment means judging that it is possible to make a U-turn at the passing point. If this is the case, the straight road priority control is prohibited and the cost information of the link and / or node stored in the cost information storage means is used for communication. The cost calculation means for calculating the cost of the route searched for the section from the point to the next passing point or destination, and the cost calculated by the cost calculating means, from the passing point to the next passing point or destination A selection means for comparing the costs of a plurality of routes searched for a section to which the user heads, and selecting one of the plurality of routes as a guide route for a section from the passing point to the next passing point or the destination; It is what has.

  The other guidance route search device according to the present invention searches for a route in a section from a passing point to a next passing point or a destination in a searching for a guiding route from a starting point via a passing point to a destination. The determination means for determining whether or not it is possible to make a U-turn at the passing point, the cost information storage means for storing the cost information of the link and / or node selected as the route, and the determination means When it is determined that it is possible to make a U-turn at the passing point, the passing on the route of the section to the passing point is performed using the cost information of the link and / or node stored in the cost information storage unit. Adjust the cost information so that it is easier to select a route that returns in the direction opposite to the approach direction than the route that goes forward in the approach direction, based on the approach direction to the point. Using the cost calculation means for calculating the cost of the route searched for the section from the passing point to the next passing point or the destination, and using the cost calculated by the cost calculating means, A selection means for comparing the costs of a plurality of routes searched for a section toward the ground and selecting one of the plurality of routes as a guide route for a section from the passing point to the next passing point or the destination. And.

  In addition to the above-described configuration of the invention, the other cost information searching device according to the present invention is configured so that the cost calculation means uses the approach direction to the passing point in the route from the passing point to the passing point as a reference. The route searched using cost information having a value smaller than the cost information of the link and / or node stored in the cost information storage means as the cost information of the link and / or node that becomes the route returning in the reverse direction The selection means selects the route with the lowest cost as the guide route for the section from the passing point to the next passing point or destination.

  In addition to the configuration of the above-described invention, the other guide route search device according to the present invention relates to the passage in the route of the section from the cost information of the link and / or node stored in the cost information storage means to the passage point. A priority coefficient storage means for storing a U-turn priority coefficient for reducing the value of the cost information when obtaining cost information of a link and / or a node that becomes a path returning in the reverse direction based on the approach direction to the point; If the cost calculation means determines that the determination means can make a U-turn at the passing point, the cost of the link and / or node that becomes a path returning in the reverse direction of the approach direction to the passing point The cost information obtained by applying the U-turn priority coefficient to the information is used to calculate the cost of the searched route, and the selection means determines whether the route with the lowest cost is the passing point. And selects a guidance route for the next passing point or toward the destination segment.

  In addition to the above-described configuration of the invention, the other route guide searching device according to the present invention is configured so that the cost calculating means calculates the cost information of a plurality of links within a predetermined number of ranges from the passing point, the predetermined number from the passing point. From the cost information of multiple links within the distance range, the cost information of multiple links from the passing point to the main road, or the first link of the route returning from the passing point, and a different road type The U-turn priority coefficient is applied to the cost information of a plurality of links up to the previous link.

  In addition to the configuration of the invention described above, the cost calculation means applies another U-turn priority coefficient according to the distance from the passing point to the next passing point or the destination. The number or range of links to be switched is switched.

  In addition to the configuration of each of the above-described inventions, the guidance route search device according to the present invention includes a facility of a predetermined genre that can be estimated by the judging means to have a parking lot or an attached parking lot at the passing point. In the case where a parking lot or a road around the site is obtained as information on a facility at the passing point, it is determined that a U-turn is possible at the passing point.

  In addition to the configuration of each of the above-described inventions, the guidance route search device according to the present invention includes a facility of a predetermined genre that can be estimated by the judging means to have a parking lot or an attached parking lot at the passing point. Or a parking lot on the site or a road around the site is obtained as information on the facility at the passing point, and the road in front of the facility at the passing point reaches the passing point. If it is possible to travel in a direction returning to the reverse direction with reference to the approach direction to the passing point in the route of the section, it is determined that a U-turn is possible at the passing point.

  The guide route search method according to the present invention, when searching for a route in a section from a passing point to a next passing point or a destination in a searching for a guiding route from a starting point via a passing point to a destination, A step of determining whether or not it is possible to make a U-turn at a passing point; and if it is determined that a U-turn can be made at the passing point, the step on the route to the passing point Proceeding to the passing point, the forward link priority control that gives priority to the link and / or node ahead is prohibited, and the cost information of the link and / or node stored in the cost information storage means is used to move from the passing point to the next Calculate the cost of the route searched for the route to the passing point or destination, and use the calculated cost to move from the passing point to the next passing point or destination. Comparing the costs of a plurality of routes searched for a section, and selecting one of the plurality of routes as a guide route for a section from the passing point to the next passing point or destination. Is.

  In another guide route search method according to the present invention, when searching for a guide route from a departure point to a destination via a passing point, a route in a section from the passing point to the next passing point or the destination is searched. If it is determined whether it is possible to make a U-turn at the passing point, and if it is determined that a U-turn is possible at the passing point, it is stored in the cost information storage means. Using the cost information of the link and / or node to return to the reverse direction of the approach direction from the route forward in the approach direction with reference to the approach direction to the pass point in the route of the section to the pass point Adjusting the cost information so that it is easier to select, and calculating the cost of the searched route for the section from the passing point to the next passing point or destination Are used to compare the costs of a plurality of routes searched for a section from the passing point to the next passing point or destination, and one route from the passing points to the next And selecting as a guide route of a section toward the passing point or the destination.

  In the present invention, a route that makes a U-turn at the passing point can be appropriately set as a guide route.

  Hereinafter, a guide route search device and a guide route search method according to embodiments of the present invention will be described with reference to the drawings. The guidance route search device will be described as a part of the car navigation system. The guide route search method will be described as a part of the operation of the car navigation system.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing a car navigation system according to Embodiment 1 of the present invention. The car navigation system searches the guide route of the vehicle from the current location or departure location to the destination via a stopover or stopover point, and guides the route so that the vehicle moves along the guide route. is there.

  The car navigation system has a main computer 1. The main computer 1 includes a CPU 2 (central processing unit) that executes programs, a RAM 3 (random access memory) that stores programs and data executed by the CPU 2, an input / output port 4 to which peripheral devices are connected, and these And a system bus 5 for connecting the two.

  The input / output port 4 includes a liquid crystal device 11, a touch panel 12, a GPS (Global Positioning System) receiver 13, a VICS (Vehicle Information and Communication System) receiver 14, cost information storage means, priority coefficient storage means, and A storage device 15 as a subordinate coefficient storage unit is connected.

  The liquid crystal device 11 has a display unit such as a liquid crystal display panel. The liquid crystal device 11 displays an image on the display unit based on the display data.

  The touch panel 12 has a transparent screen. The transparent screen is disposed so as to overlap the display unit of the liquid crystal device 11. The touch panel 12 detects a position touched by a finger in a transparent screen and outputs position information of the detected position.

  The GPS receiver 13 receives GPS radio waves from GPS satellites. The GPS radio wave has GPS satellite position information and time information. For example, when the GPS receiver 13 receives GPS radio waves from three or more GPS satellites, the GPS receiver 13 calculates the relative position of the GPS receiver 13 with respect to the plurality of GPS satellites, and the earth of the GPS receiver 13 based on the relative positions. Generate location information above. The position information on the earth is expressed, for example, as a latitude / longitude value in the world geodetic system. The GPS receiver 13 outputs the generated position information of the GPS receiver 13.

  The VICS receiver 14 receives traffic information transmitted by radio wave beacons, optical beacons or FM multiplex broadcasting. The traffic information includes traffic jam information indicating the degree of congestion on the road and traffic regulation information indicating a road closed time zone. The VICS receiver 14 outputs the received traffic information.

  The storage device 15 is configured by, for example, a hard disk drive. FIG. 2 is an explanatory diagram showing the contents stored in the storage device 15 in FIG. The storage device 15 stores a navigation program and navigation data. The navigation program includes a guidance route generation program 21 and a route guidance program 22. The navigation data includes a point data group 24, a link data group 25, a node data group 2626, a cost calculation condition list 27, and map data 28.

  The navigation program and navigation data stored in the storage device 15 are transmitted via a computer-readable recording medium or transmission medium such as a DVD (Digital Versatile Disk) -ROM (Read Only Memory), for example. It may be stored in the storage device 15. The navigation program and the navigation data may be stored in a computer-readable recording medium. In this case, the storage device 15 is configured by a drive for reading data on the recording medium.

  The point data group 24 has a plurality of records. Each record of the point data group 24 has data of one point. Each record has the name of the building, store, facility, etc. at the point, the location information of the point, and the facility information at the point. The facility information includes information such as the genre (for example, restaurant, department store, etc.) into which the facility is classified, the presence / absence of a parking lot on the site, and the presence / absence of a surrounding road in the facility. The plurality of points in the point data group 24 are points that can be selected as the destination 35, the waypoint, or the departure point.

  The link data group 25 and the node data group 26 are data that the car navigation system uses for vehicle route search and route guidance. The vehicle moves on the road. Roads have road junctions such as intersections. In the navigation system, the road branching point is handled as a node. A road between two branch points is treated as a link. Both ends of the link are connected to the node. One or more links are connected to the node.

  FIG. 3 is a diagram for explaining the relationship between roads in a certain area, links, and nodes. FIG. 3A illustrates a road in a certain area. FIG. 3B is a diagram showing nodes and links associated with the area. In FIG. 3B, each node is indicated by a square, and a link is indicated by an arrow.

  The area shown in FIG. 3A has a first national road 31, a second national road 32, a first narrow street 33, and a second narrow street 34. The first national road 31 is formed along the horizontal direction of the figure. The second national road 32 is formed along the horizontal direction of the figure and hits the first national road 31. The first narrow street 33 is formed on the left side of the second national road 32 in the drawing substantially in parallel with the second national road 32. One end of the first narrow street 33 hits the first national road 31. The second narrow street 34 is formed between the other end of the first narrow street 33 and the second national road 32 substantially in parallel with the first national road 31.

  As shown in FIG. 3B, the roads in such areas are converted into data as a plurality of links and a plurality of nodes. The node includes an intersection 36 between the first national road 31 and the second national road 32, an intersection 37 between the first national road 31 and the first narrow street 33, and the first narrow street 33 and the second narrow street 34. And the intersection 39 between the second narrow street 34 and the second national road 32. There are a total of four nodes in this region.

  In addition, a link is provided for each section between an intersection (or connection point) and an intersection (or connection point) in association with a road in such a region. Specifically, the first national road 31 has two nodes. Therefore, this two-lane road (4 lanes in total) is composed of six links. Similarly, the second national road 32 includes four links. The first narrow street 33 is composed of two links. The second narrow street 34 is composed of two links. There are a total of 14 links in this area.

  In FIG. 3A, a waypoint is set along the first narrow street 33. Hereinafter, the first narrow street 33 which is the road in front of the transit point is referred to as a transit point road. As shown in FIG. 3B, the first narrow street 33 has two links L3 and L4. The links L3 and L4 are reverse links. The first narrow street 33 is a road that can be passed in both directions.

  The link data group 25 has a plurality of records. Each record of the link data group 25 has one link data. Each record contains traffic regulation information about the link, the distance of the link, cost information passing through the link, the road type to which the link corresponds (for example, highway, toll road, narrow street, etc.), specific to the link An identification number, an identification number of a node to which the link is connected, and the like. The traffic regulation information regarding the link includes, for example, information such as a one-way road, time zone prohibition, right turn prohibition, U-turn prohibition, and road width (width). Each record may be associated with all links of one road instead of one link.

  The node data group 26 has a plurality of records. Each record of the node data group 26 has data of one node. Each record includes position information of the node, traffic regulation information related to the node, cost information passing through the node, an identification number unique to the node, an identification number of a link connected to the node, and the like. Examples of the traffic regulation information regarding the node include information such as presence / absence of traffic lights, prohibition of right turn, prohibition of U-turn, and the like.

  The cost information passing through the node and the cost information passing through the link have values according to the ease of passing or the difficulty of passing. Such cost information has such a large value that it is difficult to pass through.

  Note that the cost information itself actually used for the calculation is stored in the storage device 15 in association with, for example, the road type, and each record of the node data group 26 and the link data group 25 has designation information of this type. It may be a data structure. In addition, the value of the cost information is not a value that depends only on the ease of passing, but for example, a value that depends on the road toll free, a value that depends on the ease of driving on the road, or a value that depends on the quality of the road scenery It may be a value according to the traffic volume on the road, or a value obtained by combining them.

  Returning to FIG. 2, the cost calculation condition list 27 stored in the storage device 15 has a calculation condition for calculating the cost of the route. Specifically, for example, the cost calculation condition list 27 stores various coefficients such as a traffic congestion coefficient and a straight road priority coefficient.

  The traffic congestion coefficient is a coefficient that is multiplied by cost information of links and nodes that are congested. The straight driving priority coefficient has a value greater than one. As a result, it is possible to increase the cost of passing links and nodes that are congested.

  For example, when a first route toward a certain waypoint is generated and a second route starting from that route point is searched, the route straight ahead is assumed to be straight on the way road. For example, a route is relatively easy to select as a guide route compared to a route that returns on a road in front of the route. In other words, it is easy to select the route passing in front of the waypoint as the second route. In the example of the waypoint in FIG. 3, when the link of the route before the route in the first route toward the route is the link L3, the link from the link L4 is the link of the route before the route in the second route. This is to facilitate selection of L3. The straight road priority coefficient is a coefficient that is multiplied by the cost information of the link corresponding to the straight road. The straight driving priority coefficient has a value smaller than 1. Thereby, the passage cost of the road which goes straight along the road can be reduced.

  The map data 28 is data used for displaying a map on the liquid crystal display. Examples of such map data 28 include two-dimensional or three-dimensional vector map data 28. The vector map data 28 includes background data serving as a map background image and vector data drawn on the background image. The background image is image data obtained by color-coding a park, a river, a pond, and the like, for example. The vector data is, for example, drawing data for each road. The map data 28 may also include landmark three-dimensional polygon data, icon data associated with each point, and the like.

  The guide route generation program 21 is executed by the CPU 2 to realize various functions for generating a guide route in the main computer 1. FIG. 4 is a block diagram showing functions realized in the car navigation system by the CPU 2 in FIG. 1 executing the guide route generation program 21. The CPU 2 in FIG. 1 executes the guide route generation program 21, so that a point setting unit 41, a cost calculation condition setting unit 42 as a determination unit, a candidate route generation unit 43, and a cost calculation unit as a cost calculation unit 44 and a guide route selection unit 45 as selection means are realized.

  The point setting unit 41 displays facility information and the like stored in the point data group 24 on the liquid crystal device 11 and selects a point selected by the touch panel 12 based on the display as a departure point, a transit point, or a destination. To do. The point setting unit 41 displays a map based on the map data 28 on the liquid crystal device 11 and selects a stop point selected by the touch panel 12 from the display as a departure point, a transit point, or a destination. The point setting unit 41 stores the selected departure point, waypoint, or destination in the storage device 15.

  Based on the cost calculation condition list 27, the cost calculation condition setting unit 42 generates a cost calculation condition 46 corresponding to the situation of the vehicle at the time of search and stores it in the storage device 15. The cost calculation condition 46 has, for example, a straight road priority coefficient in a situation where a search is made with a straight road priority.

  The candidate route generation unit 43 uses the link data group 25 and the node data group 26 to search for a route from the search start point to the end point, and stores it in the storage device 15. The searched route is obtained by connecting the starting point and the ending point of the search with one or more links and nodes. The candidate route generation unit 43 stores the searched route data in the storage device 15 as a candidate route. A candidate route list 47 is stored in the storage device 15 by a plurality of candidate routes.

  The cost calculation unit 44 calculates the cost of the candidate route searched by the candidate route generation unit 43 under the set cost calculation condition 46.

  The guide route selection unit 45 selects the candidate route with the lowest cost as the guide route 48 and stores it in the storage device 15.

  The route guidance program 22 is executed by the CPU 2 to realize various functions for guiding the route to the main computer 1. FIG. 5 is a block diagram showing functions realized in the car navigation system by the CPU 2 in FIG. 1 executing the route guidance program 22. When the CPU 2 in FIG. 1 executes the route guidance program 22, a route guidance unit 56 as route guidance means is realized.

  The route guide unit 56 reads the guide route 48 and the map data 28 stored in the storage device 15, and uses them to display the guide route 48 and a map around the current location on the liquid crystal device 11. The route guidance unit 56 may output voice guidance from a speaker (not shown) as necessary.

  Next, the operation of the car navigation system according to Embodiment 1 having the above configuration will be described. First, referring to FIG. 3 and FIG. 4, a search process for searching for a guide route 48 of a vehicle heading to a destination from a current location or a departure location via a passing point such as a transit point or a stop point will be described.

  FIG. 6 is a flowchart showing the overall operation during the route search of the car navigation system shown in FIG.

  The point setting unit 41 displays facility information stored in the map data group 24 and a map based on the map data 28 on the liquid crystal device 11 as a selection screen for starting point, passing point, or destination. The point setting unit 41 selects a facility or a point on the map as a departure point, a passing point, or a destination from the facility or map displayed on the liquid crystal device 11 based on the position information of the detection position from the touch panel 12. (Step ST1). Referring to FIG. 3, the point setting unit 41 selects a departure place far to the right of the first national road 31, selects a waypoint along the first narrow street 33 (the road in front of the waypoint), and further A destination is selected to the left of one national highway 31.

  When the point setting unit 41 selects the departure point, the passing point, and the destination, the point setting unit 41 instructs the cost calculation condition setting unit 42 to start searching. The cost calculation condition setting unit 42 starts the route searching process for the first section (step ST2).

  FIG. 7 is a flowchart showing detailed steps of the route searching process (step ST2) in the first section in FIG. In the route search processing for the first section (step ST2), the cost calculation condition setting unit 42 selects the starting point or the current location selected by the point setting unit 41 as the search starting point, and selects the passing point as the search end point. To do. If there are a plurality of passing points, the first passing point is selected as the search end point. In FIG. 3, the cost calculation condition setting unit 42 selects the departure point as the starting point of the search, and selects the waypoints as the ending point of the search.

  After selecting the starting point and the ending point of the search, the cost calculation condition setting unit 42 sets a route search condition for searching for a route in the first section (step ST11). Specifically, the cost calculation condition setting unit 42 causes the storage device 15 to store the traffic congestion coefficient stored in the cost calculation condition list 27 as the cost calculation condition 46.

  When the setting process of the cost calculation condition 46 is completed, the cost calculation condition setting unit 42 instructs the candidate route generation unit 43 to generate a candidate route. Note that the cost calculation condition setting unit 42 may instruct the candidate route generation unit 43 to generate a candidate route before starting the setting process of the cost calculation condition 46.

  Candidate route generation unit 43 generates a candidate route using link data group 25 and node data group 26 (step ST12). Specifically, the candidate route generation unit 43 connects the links to the nodes using the position information of the nodes and the connection information for the nodes of the links, and generates a chain of links from the starting point to the ending point of the search. The candidate route generation unit 43 generates a chain of links from the search start point to the end point as a candidate route.

  In this candidate route generation processing, the candidate route generation unit 43 refers to information such as the link data group 25, the node data group 26, the traffic jam / traffic regulation information 51, and searches for a route that can be traveled. For example, if there is traffic regulation information such as a U turn prohibition or a right turn prohibition other than an intersection on the first national road 31 in FIG. Candidate routes to turn or turn right are not generated.

  If the candidate route generation unit 43 is away from the road used for the route search (hereinafter referred to as a search road) because the starting point or end point of the search is specified on the map, the candidate route generation unit 43 Needs to specify the pull-in point used for the search instead of the start point or end point of the search.

  The pull-in point may simply be the closest point of the search road closest to the starting point or the end point, but in reality, it is not simply determined based on the distance, but how the pull-in point is used (starting point, destination, (Passing point etc.), the attribute of the pull-in point, and the type of search road where the pull-in point is to be placed may be determined. Specifically, for example, the candidate route generation unit 43 first extracts a search road that falls within a predetermined range (for example, 50 m) centering on the start point or the end point, and specifies a candidate of a pull-in point on each search road. . The pull-in point is, for example, a point where the search road is connected to a narrow street following the start point or the end point. Normally, a plurality of pull-in point candidates are specified by this specifying process. If there is no search road within the predetermined range, the candidate route generation unit 43 may further widen the search range. The predetermined range may be an ellipse range, for example, when the starting point is the starting point.

  When a plurality of pull-in point candidates are specified, the candidate route generation unit 43 narrows down the pull-in point candidates. Specifically, for example, the candidate route generation unit 43 specifies a candidate for the closest pulling point from the starting point or the end point, and adds a predetermined short distance (for example, 50 m) to the distance to the closest pulling point candidate. The pull-in point candidates are selected as pull-in points used for the search. In addition, the candidate route generation unit 43 includes a road type (for example, an expressway, a national road, etc.) and a link type (for example, vertical line non-separation, vertical line separation (for example, roads) in the link information of the search road on which the candidate for the pull-in point is placed. For example, based on the road having a median strip), a side road, a dummy link, etc., for example, if it is not a dummy link, it is left as its pull-in point, thereby narrowing the pull-in points used for the search. If a plurality of pull-in points used for the search remain, the candidate route generation unit 43 searches for a candidate route for each pull-in point.

  The candidate route generation unit 43 stores the generated candidate route in the storage device 15. As a result, the candidate route list 47 is stored in the storage device 15.

  When the candidate route is stored in the storage device 15, the cost calculation unit 44 calculates the cost of each candidate route (step ST13). The cost calculation unit 44 first calculates an individual passage cost for each link and each node included in the chain of links of the candidate route.

  At this time, the cost calculation unit 44 multiplies the congestion coefficient for the link of the road where the traffic jam occurs in the traffic jam / traffic regulation information 51. The congestion coefficient is a coefficient of 1 or more. As a result, the cost of passing through a congested route increases.

  For links and nodes for which no coefficient is set in the cost calculation condition 46, the cost calculation unit 44 keeps the cost information in the link data group 25 or the node data group 26 of the link or node as it is, and links or nodes individually. Let it be a transit cost.

  After calculating the individual passage costs of all the links and all the nodes included in the candidate route, the cost calculation unit 44 adds all the individual passage costs and sets the calculation result as the cost of the candidate route. Note that the cost calculation unit 44 may calculate the cost of the candidate route by multiplying individual passage costs for each link or node, or by calculating with a predetermined arithmetic expression.

  When the cost of each candidate route stored in the storage device 15 is calculated, the guide route selection unit 45 has the highest cost among the plurality of candidate routes (candidate route list 47) stored in the storage device 15. A low candidate route is selected (step ST14).

  The guide route selection unit 45 stores the selected candidate route in the storage device 15 as the guide route 48. Through the search process for the guide route 48 described above, the guide route 48 of the first section is stored in the storage device 15. In the case of FIG. 3, the route from the first national road 31 to the first narrow street 33, in FIG. 3B, the route “L1 → N1 → L2 → N2 → L3” serves as the guide route, and the storage device 15 is stored.

  When the guide route 48 of the first section is stored in the storage device 15, returning to FIG. 6, the cost calculation condition setting unit 42 passes all the passing points from the starting point or the current location selected by the point setting unit 41. It is then determined whether or not the search for the route to the destination has been completed (step ST3). For example, when the end point in the last search is the destination, the cost calculation condition setting unit 42 may determine that the search for the route passing through all the passing points has been completed.

  As in the case of FIG. 3, when the end point of the guide route 48 in the first section is a passing point, the cost calculation condition setting unit 42 starts a route search process for the next section (step ST4).

  FIG. 8 is a flowchart showing detailed steps of the route searching process (step ST4) of the next section in FIG.

  In the route search processing for the next section (step ST4), the cost calculation condition setting unit 42 selects the end point of the previous search as the search start point, and selects the next passing point as the search end point. If there is no next passing point, the destination is selected as the end point of the search. In the case of FIG. 3, the waypoint is selected as the search starting point, and the destination is selected as the search end point. After selecting the search start point and end point for the route search processing of the next section, the cost calculation condition setting unit 42 starts setting the route search condition for searching the route of the next section.

  In the route search condition setting process, the cost calculation condition setting unit 42 first stores the congestion coefficient stored in the cost calculation condition list 27 in the storage device 15 as the cost calculation condition 46 (step ST21).

  Further, the cost calculation condition setting unit 42 determines whether or not a U-turn is possible at the starting point based on the point data group 24 (step ST22). The point data group 24 stores, as facility information for each point, the genre (for example, restaurants, department stores, etc.), the presence / absence of a parking lot in the site, the presence / absence of a surrounding road in the facility, and the like.

  Therefore, the cost calculation condition setting unit 42 refers to the point data group 24 and, for example, determines that a U-turn is possible at the starting point of the search when the facility at the starting point of the search is a large store such as a department store. In addition to this, for example, the cost calculation condition setting unit 42 refers to the point data group 24, and a facility of a predetermined genre that can be estimated that the facility at the starting point of the search is a parking lot such as a parking lot or a chain store. If it is, it is determined that a U-turn is possible at the starting point of the search.

  In addition, the cost calculation condition setting unit 42 refers to the point data group 24 and can make a U-turn at the starting point of the search when a parking lot or a road around the site is obtained as information on the facility at the starting point of the search. It is judged that.

  Then, if the cost calculation condition setting unit 42 does not determine that a U-turn is possible at the starting point of the search, the cost calculation condition setting unit 42 sets a straight road priority coefficient as the cost calculation condition 46 (step ST23).

  When it is determined that a U-turn is possible at the starting point of the search, the cost calculation condition setting unit 42 further determines whether it is possible to return on the road before the starting point of the search. Based on the link data group 25 and the node data group 26, the cost calculation condition setting unit 42 determines whether or not the road before the starting point can be returned (step ST24). The link data group 25 has a link for each traveling direction of the road. In addition, a plurality of links that are opposite lanes on one road generally have a common part in the identification number.

  Therefore, for example, the cost calculation condition setting unit 42 first searches the link data group 25 to determine whether there is a link having an identification number having a predetermined common part with the last link of the guide route in the section to the starting point. Judging. If there is an oncoming lane link that satisfies the condition, the cost calculation condition setting unit 42 determines that the road before the search starting point is a road that can be returned.

  In FIG. 3, when searching for a route from a stopover to a destination, a stopover road is a road before the starting point of the search. Then, when the link L3 is selected as the last link of the guidance route of the section to the waypoint, the cost calculation condition setting unit 42 extracts the link L4 as the link of the opposite lane. Based on the extraction of the opposite lane link, the cost calculation condition setting unit 42 determines that the road before the starting point is a road that can be returned.

  If the cost calculation condition setting unit 42 does not determine that the road before the search starting point is a returnable road, the cost calculation condition setting unit 42 sets the straight road priority coefficient as the cost calculation condition 46 (step ST23). .

  When the U-turn is not possible at the starting point of the search by the above setting process of the cost calculation condition 46, the cost calculation condition setting unit 72 sets a traffic congestion coefficient and a road straight ahead priority coefficient as the cost calculation condition 46. If the U-turn is possible at the starting point of the search but the road before the starting point of the search is not a road that can return, the cost calculation condition setting unit 72 sets the traffic congestion coefficient and the cost calculation condition 46 as the cost calculation condition 46. Set the straight ahead priority coefficient. On the other hand, when the U-turn is possible at the starting point of the search and the road before the starting point of the search can return, the cost calculation condition setting unit 72 sets the traffic congestion as the cost calculation condition 46. Set the coefficient.

  When the setting process of the cost calculation condition 46 is completed, the cost calculation condition setting unit 42 instructs the candidate route generation unit 43 to generate a candidate route. The candidate route generation unit 43 uses the link data group 25 and the node data group 26 to generate a candidate route composed of a chain of links from the search start point to the end point (step ST25). The candidate route generation unit 43 stores the generated candidate route in the storage device 15. As a result, the candidate route list 47 is stored in the storage device 15.

  When the candidate route is stored in the storage device 15, the cost calculation unit 44 calculates the cost of each candidate route (step ST26). The cost calculation unit 44 first calculates an individual passage cost for each link and each node included in the chain of links of the candidate route.

  At this time, the cost calculation unit 44 multiplies the congestion coefficient for the link of the road where the traffic jam occurs in the traffic jam / traffic regulation information 51. The congestion coefficient is a coefficient of 1 or more. This increases the cost of passing a congested link.

  Further, when a straight road priority coefficient is set as the cost calculation condition 46, the cost calculation unit 44 uses the direction of the last link in the search route of the previous section as a reference along the direction of the last link. Multiply the straight path priority coefficient for the link of the route to go. The straight driving priority coefficient is a coefficient of 1 or less. Thereby, the passing cost of the link corresponding to the straight road priority is reduced. Here, the cost of the link of the route along the direction of the last link is relatively lowered by the road priority coefficient, but instead, the road priority coefficient of a value greater than 1 is set to the last link. You may make it apply to the cost of the link of the path | route which goes in the direction opposite to (1).

  Note that the cost calculation unit 44 basically only has to multiply the cost information for the first link of the candidate route by the straight driving priority coefficient. In addition to this, for example, the cost calculation unit 44, for a predetermined number (for example, 10) of a plurality of links from the first link of the candidate route, multiplies the cost information by a straight ahead priority coefficient, For a plurality of links within a predetermined distance range (for example, 2 km), the cost information is multiplied by a straight ahead priority coefficient on the cost information, or the cost information is obtained for a plurality of links from the search starting point to the main road. Multiply by the road straight ahead priority coefficient, or multiply the cost information by the road straight ahead priority coefficient for multiple links until the road type is different from the road link before the starting point of the search. Also good.

  For links and nodes for which no coefficient is set in the cost calculation condition 46, the cost calculation unit 44 keeps the cost information in the link data group 25 or the node data group 26 of the link or node as it is, and links or nodes individually. Let it be a transit cost.

  After calculating the individual passage costs of all the links and all the nodes included in the candidate route, the cost calculation unit 44 adds all the individual passage costs and sets the calculation result as the cost of the candidate route. Note that the cost calculation unit 44 may calculate the cost of the candidate route by multiplying individual passage costs for each link or node, or by calculating with a predetermined arithmetic expression.

  When the cost of each candidate route stored in the storage device 15 is calculated, the guide route selection unit 45 has the highest cost among the plurality of candidate routes (candidate route list 47) stored in the storage device 15. A low candidate route is selected (step ST27).

  The guide route selection unit 45 stores the selected candidate route in the storage device 15 as the guide route 48. Through the search process for the guide route 48 described above, the guide route 48 of the next section is stored in the storage device 15. In the case of FIG. 3, the guide route 48 of the section from the waypoint to the destination is stored in the storage device 15.

  When the guide route 48 of the next section is stored in the storage device 15, returning to FIG. 6, the cost calculation condition setting unit 42 determines whether or not the end point in the last search is the destination. It is determined whether or not the search for the route from the starting point or the current point selected by 41 through all passing points to the destination is completed (step ST3).

  As shown in FIG. 3, when the end point in the last search is the destination, the cost calculation condition setting unit 42 ends the search process. When the end point in the last search is not the destination, the cost calculation condition setting unit 42 repeatedly executes the above-described route search process (step ST4) until the end point in the last search becomes the destination. To do.

  When the search processing for all sections is completed by the above processing, the storage device 15 stores the guidance of the vehicle from the current location or the departure location to the destination via a transit point such as a transit point or a stop point. Path 48 is stored.

  Next, route guidance using the guidance route 48 will be described with reference to FIG.

  The route guide unit 56 reads position information from the GPS receiver 13. The route guide unit 56 reads the guide route 48 and the map data 28 around the host vehicle from the storage device 15 using the position information from the GPS receiver 13 as the position information of the host vehicle. The route guide unit 56 generates display data from the read guide route 48 and the map data 28. The route guide unit 56 generates display data including the vehicle position mark. The route guide unit 56 outputs the generated display data to the liquid crystal device 11. The liquid crystal device 11 displays a map and a guide route 48 on the display unit based on the display data.

  The route guide unit 56 periodically reads position information from the GPS receiver 13. The route guide unit 56 determines whether or not the position of the own vehicle specified by the position information from the GPS receiver 13 has moved from the position of the own vehicle position mark displayed on the liquid crystal device 11.

  If it is determined that the position of the host vehicle has moved, the route guide unit 56 reads the guide route 48 and the map data 28 around the host vehicle from the storage device 15 based on the position of the new host vehicle, and displays the display data. Generate. The liquid crystal device 11 displays the display data generated by the route guide unit 56.

  Note that the route guidance unit 56 may generate new display data without reading the movement of the vehicle position after reading the position information from the GPS receiver 13. The route guide unit 56 may determine the current location of the host vehicle based on information on a movement amount and a movement direction from a gyro sensor (not shown).

  Thus, in the route guidance, the car navigation system uses the position information from the GPS receiver 13 as the position information of the own vehicle, and displays the map around the position of the own vehicle and the guide route 48 on the liquid crystal device 11. Keep doing. Therefore, when the vehicle driver drives the vehicle so that the vehicle position mark moves along the guide route 48 displayed on the liquid crystal device 11, the vehicle moves from the current location or the like to the destination or waypoint. To do.

  As described above, the car navigation system according to the first embodiment searches for the guide route 48 from the departure point or the current location to the destination via the waypoint or stop point, and the vehicle The route can be guided to move along 48.

  In particular, when a U-turn is possible at a stopover point or a stop point, and the road in front of the stop point or stop point can be returned, the car navigation system according to the first embodiment is A route that makes a U-turn at the waypoint or stop point can be generated as the guide route 48.

  For example, in FIG. 3A, a transit point is set along the first narrow street 33, a departure place is set to the far right of the first national road 31, and the destination is set to the far left of the first national road 31. The ground is set. Under the setting of such points, the guide route 48 of the section from the departure point to the waypoint enters the first narrow street 33 from the first national road 31 as shown by the broken line in FIG. In the case of a route (in the case of FIG. 3B, the route “L1 → N1 → L2 → N2 → L3”), if there is a parking lot at the waypoint, the road is preferentially forbidden, and FIG. As shown by the one-dot chain line in (A), a route that makes a U-turn at the transit point and returns directly from the first narrow street 33 to the first national road 31 (in FIG. 3B, “L4 → N2 → L5 ”) is generated as the route of the section from the waypoint to the destination.

  Further, in the first embodiment, based on the determination as to whether or not a U-turn can be made at the waypoint, it is controlled whether or not the straight road priority coefficient is set as the cost calculation condition 46, and a candidate route with a low cost is selected. Finally, the route is selected as the guide route 48 for each section. Therefore, even if it is determined that a U-turn can be made at the waypoint, depending on the route cost, a candidate route that goes straight along the road can be selected as the guide route 48. For example, the route indicated by a two-dot chain line in FIG. 3A, that is, the first narrow street 33, the second narrow street 34, and the second national road 32, the first one-side two-lane road 32. The route returning to (in FIG. 3B), the route “L3-> N3-> L6-> N4-> L7-> N1-> L2-> N2-> L5” can be selected as the guide route 48.

Embodiment 2. FIG.
FIG. 9 is a block diagram showing functions realized when searching for a guidance route in the car navigation system according to Embodiment 2 of the present invention.

  The cost calculation condition list 61 stored in the storage device 15 stores various coefficients such as a congestion coefficient, a road priority coefficient, and a U-turn priority coefficient.

  The U-turn priority means that, for example, when a first route to a certain waypoint is generated and a second route starting from that waypoint is searched for, This is to make it relatively easy to select as a guide route compared to a route that goes straight along a road on a route in front of a route. In other words, it is easy to select the route that turns back at the waypoint as the second route. In the example of the waypoint in FIG. 3, when the link of the road before the route in the first route toward the route is the link L3, the link from the link L3 is the link of the road before the route in the second route. This is to facilitate selection of L4. The U-turn priority coefficient is a coefficient that is multiplied by the cost information of the link corresponding to the road of the U-turn. The U-turn priority coefficient has a value smaller than 1. Thereby, the passage cost of the U-turn road can be reduced.

  Based on the cost calculation condition list 61, the cost calculation condition setting unit 62 generates a cost calculation condition 46 corresponding to the situation of the vehicle at the time of search and stores it in the storage device 15. The cost calculation condition 46 has, for example, a U-turn priority coefficient in a situation where searching is performed with U-turn priority. The cost calculation condition setting unit 62 functions as a determination unit.

  The cost calculation unit 63 calculates the cost of each candidate route stored in the storage device 15 as the candidate route list 47. The cost calculation unit 63 functions as a cost calculation unit.

  The other constituent elements shown in FIG. 9 have the same functions as the constituent elements of the same name according to the first embodiment, and the same reference numerals as those of the constituent elements of the first embodiment are attached and the description thereof is omitted. To do. Further, in the car navigation system according to the second embodiment, the function realized at the time of route guidance is the same as that of the first embodiment, and the description thereof is omitted.

  The cost calculation condition setting unit 62 and the cost calculation unit 63 are configured such that the guide route generation program stored in the storage device 15 is executed by the CPU 2 so that the point setting unit 41, the candidate route generation unit 43, and the guide route selection are performed. This is realized together with the unit 45.

  Next, the operation of the car navigation system according to Embodiment 2 having the above configuration will be described.

  In the car navigation system according to the second embodiment, after the departure point, the passing point, and the destination are set, the guidance is performed in accordance with the flowchart at the time of route search shown in FIG. 6 as in the car navigation system of the first embodiment. The generation process of the path 48 is executed. Then, the car navigation system according to Embodiment 2 determines whether or not the route search is completed (step ST3) when the guidance route 48 of the first section is completed (step ST3). When the route search is not completed, the car navigation system according to Embodiment 2 starts the route search process for the next section (step ST4). When the departure point, the waypoint, and the destination are set as shown in FIG. 3, the car navigation system according to the second embodiment starts the route searching process for the section from the waypoint to the destination.

  FIG. 10 is a flowchart showing detailed steps of the route searching process (step ST4) for the next section in the car navigation system according to the second embodiment.

  In the route searching process for the next section (step ST4), the cost calculation condition setting unit 62 selects the end point of the previous search as the search start point, and selects the next passing point as the search end point. If there is no next passing point, the destination is selected as the end point of the search. After selecting the search start point and end point for the route search processing of the next section, the cost calculation condition setting unit 62 starts setting the route search condition for searching the route of the next section.

  In the route search condition setting process, the cost calculation condition setting unit 62 first stores the congestion coefficient stored in the cost calculation condition list 61 in the storage device 15 as the cost calculation condition 46 (step ST21).

  The cost calculation condition setting unit 62 determines whether or not a U-turn is possible at the starting point of the search based on the point data group 24 (step ST22). Then, when the cost calculation condition setting unit 62 does not determine that a U-turn is possible at the starting point of the search, the cost calculation condition setting unit 62 sets the straight driving priority coefficient as the cost calculation condition 46 (step ST23).

  When it is determined that a U-turn is possible at the starting point of the search as in the case of FIG. 3, the cost calculation condition setting unit 62 further determines whether it is possible to return on the road before the starting point of the search. . Based on the link data group 25 and the node data group 26, the cost calculation condition setting unit 42 determines whether or not the road before the starting point can be returned (step ST24). If the cost calculation condition setting unit 62 does not determine that the road before the search starting point is a returnable road, the cost calculation condition setting unit 62 sets a straight driving priority coefficient as the cost calculation condition 46 (step ST23). .

  When determining that the road before the starting point of the search is a road that can be returned, the cost calculation condition setting unit 62 sets the U-turn priority coefficient as the cost calculation condition 46 (step ST31).

  When the U-turn is not possible at the starting point of the search by the above setting process of the cost calculation condition 46, the cost calculation condition setting unit 72 sets a traffic congestion coefficient and a road straight ahead priority coefficient as the cost calculation condition 46. Further, even if a U-turn is possible at the starting point of the search, if the road is not capable of returning to the road before the starting point of the search, the cost calculation condition setting unit 72 sets the congestion coefficient and the cost calculation condition 46 as the cost calculation condition 46. Set the straight ahead priority coefficient. On the other hand, when the U-turn is possible at the starting point of the search and the road can return to the road before the starting point of the search, the cost calculation condition setting unit 72 sets the traffic congestion as the cost calculation condition 46. Set coefficient and U-turn priority coefficient.

  When the setting process of the cost calculation condition 46 is completed, the cost calculation condition setting unit 62 instructs the candidate route generation unit 43 to generate a candidate route. The candidate route generation unit 43 uses the link data group 25 and the node data group 26 to generate a candidate route composed of a chain of links from the search start point to the end point (step ST25). The candidate route generation unit 43 stores the generated candidate route in the storage device 15. As a result, the candidate route list 47 is stored in the storage device 15.

  When the candidate route is stored in the storage device 15, the cost calculation unit 63 calculates the cost of each candidate route (step ST26). The cost calculation unit 63 first calculates an individual passage cost for each link and each node included in the chain of links of the candidate route.

  At this time, for the link of the road where the traffic jam occurs in the traffic jam / traffic regulation information 51, the cost calculation unit 63 multiplies the traffic jam coefficient for the link. The congestion coefficient is a coefficient of 1 or more. This increases the cost of passing a congested link.

  Further, when the straight road priority coefficient is set as the cost calculation condition 46, the cost calculation unit 63 uses the direction of the last link in the search route of the previous section as a reference along the direction of the last link. Multiply the straight path priority coefficient for the link of the route to go. The straight driving priority coefficient is a coefficient of 1 or less. Thereby, the passing cost of the link corresponding to the straight road priority is reduced.

  Further, when the U-turn priority coefficient is set as the cost calculation condition 46, the path of the route that travels in the opposite direction with respect to the direction opposite to the direction of the last link in the search route of the previous section is straight on the road. Multiply by priority factor. The U-turn priority coefficient is a coefficient of 1 or less. Thereby, the passing cost of the link corresponding to the U-turn priority is lowered. Here, the cost of the link of the route that travels in the direction opposite to the direction of the last link is relatively lowered by the U-turn priority coefficient, but instead, a U-turn priority coefficient having a value greater than 1 is used. You may make it apply to the cost of the link of the path | route which goes along the direction of this link.

  Note that the cost calculation unit 44 basically only has to multiply the cost information for the first link of the candidate route by the U-turn priority coefficient. In addition to this, for example, the cost calculation unit 44 multiplies a predetermined number (for example, 10) of a plurality of links from the first link of the candidate route by multiplying the cost information by a U-turn priority coefficient, or predetermined from the search starting point. For a plurality of links within a distance range (for example, 2 km), the cost information is multiplied by a U-turn priority coefficient, or the U-turn is added to the cost information for a plurality of links from the starting point of the search to the main road. The cost information may be multiplied by the U-turn priority coefficient for a plurality of links up to a road type different from the link of the road before the search starting point.

  For links and nodes for which no coefficient is set in the cost calculation condition 46, the cost calculation unit 63 keeps the cost information in the link data group 25 or the node data group 26 of the link or node as it is, and links or nodes individually. Let it be a transit cost.

  After calculating the individual passage costs of all the links and all the nodes included in the candidate route, the cost calculation unit 63 adds all the individual passage costs and sets the calculation result as the cost of the candidate route.

  When the cost of each candidate route stored in the storage device 15 is calculated, the guide route selection unit 45 has the highest cost among the plurality of candidate routes (candidate route list 47) stored in the storage device 15. A low candidate route is selected (step ST27).

  The guide route selection unit 45 stores the selected candidate route in the storage device 15 as the guide route 48. Through the search process for the guide route 48 described above, the guide route 48 of the next section is stored in the storage device 15. In the case of FIG. 3, the guide route 48 of the section from the waypoint to the destination is stored in the storage device 15.

  When the guide route 48 of the next section is stored in the storage device 15, returning to FIG. 6, the cost calculation condition setting unit 62 determines whether or not the end point in the last search is the destination. It is determined whether or not the search for the route from the starting point or the current point selected by 41 through all passing points to the destination is completed (step ST3).

  As shown in FIG. 3, when the end point in the last search is the destination, the cost calculation condition setting unit 62 ends the search process. If the end point in the last search is not the destination, the cost calculation condition setting unit 62 repeatedly executes the above-described route search process (step ST4) until the end point in the last search becomes the destination. To do.

  The route guidance using this guidance route 48 is the same as that in the car navigation system according to the first embodiment, and the description thereof is omitted.

  As described above, the car navigation system according to the second embodiment searches the guide route 48 from the departure point or the current location to the destination via the waypoint or stop point, and the vehicle The route can be guided to move along 48.

  In particular, in the case where the U-turn is possible at a stopover point or a stop point and the road in front of the stop point or stop point can be returned, the car navigation system according to the second embodiment is The cost of the U-turn route at the waypoints and drop-off points is reduced. As a result, in the car navigation system according to the second embodiment, a route that makes a U-turn at the waypoint or stopover point is easily selected as the guide route 48.

  In the second embodiment, whether or not a U-turn priority coefficient or a U-turn priority coefficient is set as the cost calculation condition 46 is controlled based on the determination as to whether or not a U-turn is possible at the waypoint, The candidate route with a low value is finally selected as the guide route 48 of each section. Therefore, even if it is determined that a U-turn can be made at the waypoint, a candidate route that goes straight along the road can be selected as the guide route 48.

  Each of the above embodiments is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes can be made without departing from the scope of the invention. It is.

  For example, in each of the above-described embodiments, the cost calculation condition setting units 42 and 62 determine whether or not a U-turn is possible at a passing point that is a starting point of the search for each section, and the road in front of the passing point may turn back. Based on whether or not the road is possible, it is determined whether or not a U-turn at the passing point is possible, and a coefficient set as the cost calculation condition 46 is selected. In addition to this, for example, the cost calculation condition setting units 42 and 62 determine whether or not a U-turn at the passing point is possible based only on whether or not a U-turn is possible at the passing point, and the cost calculating condition 46 Or a coefficient to be set may be selected.

  In each of the above embodiments, the cost calculation condition setting units 42 and 62 determine whether or not a U-turn is possible at the passing point based on the facility information of the point data group 24 stored in the storage device 15. ing. In addition to this, for example, the cost calculation condition setting units 42 and 62 determine whether or not a U-turn is possible at the passing point based on, for example, information on the facility at the passing point acquired via a wireless communication network or the like. You may make it judge.

  In each of the above embodiments, the cost calculation condition setting units 42 and 62 can make a U-turn at a passing point that is a starting point of a search for each section, and can turn back a road in front of the passing point. When it is a road, the setting of the straight road priority coefficient is stopped or the U-turn priority coefficient is set. In addition to this, for example, the cost calculation condition setting units 42 and 62 may change the road type when the road type of the road that is curved to the road is a higher road than the road type of the road before the passing point. You may make it stop setting the straight ahead priority coefficient, or set a U-turn priority coefficient. For example, in FIG. 3, the cost calculation condition setting units 42 and 62 include the road type of the first narrow street 33 that is a transit road and the first national road 31 that has made a left turn to the first narrow street 33. Based on the comparison with the road type, the setting of the straight driving priority coefficient may be stopped or the U-turn priority coefficient may be set. In addition, for example, the cost calculation condition setting units 42 and 62 may determine that the road type of the first national road 31 turning left to the first narrow street 33 that is a transit road is a main road. May stop setting the straight ahead priority coefficient on the road or set the U-turn priority coefficient.

  In addition to this, for example, the cost calculation condition setting units 42 and 62 compare the direction of the end point based on the starting point of the search with the direction of the return link on the road before the start point, and the angle formed by these directions is When the angle is equal to or less than a predetermined angle (for example, 90 degrees, 60 degrees, 45 degrees, etc.), the straight road priority coefficient setting may be stopped, or the U-turn priority coefficient may be set. For example, in FIG. 3, the cost calculation condition setting units 42 and 62 include the direction of the destination based on the waypoint and the link L4 that is the return link of the first narrow street 33 that is the road in front of the waypoint. When the angle between the directions is 60 degrees or less, the setting of the straight ahead priority coefficient or the U-turn priority coefficient may be set. In addition, for example, the cost calculation condition setting units 42 and 62 pass the first national road 31 that has turned left into the first narrow street 33 that is a transit road between the start point and the end point of the search. If it is, the setting of the straight ahead priority coefficient may be stopped, or the U-turn priority coefficient may be set.

  In each of the above embodiments, the cost of the candidate route is calculated by multiplying the coefficient individually for each link or node and adding it. In addition, for example, the cost of the entire route obtained based only on the cost information of the link data group and the node data group may be multiplied by a coefficient, and the calculation result may be calculated as the cost of the candidate route. .

  In the above embodiments, the cost calculation units 44 and 63 calculate one cost for each candidate route. In addition to this, for example, the cost calculation units 44 and 63 may calculate a plurality of costs for each candidate route. In this case, the guide route selection unit 45 may make a comprehensive determination based on a plurality of costs of each candidate route, and select a route that seems to be optimal as the guide route.

  The above embodiments are examples when the present invention is applied to a car navigation system. In addition to this, for example, the present invention can be applied to a navigation system for guiding routes such as bicycles and motorcycles. Further, the navigation system may be composed of a mobile phone terminal and a navigation server connected to the mobile phone terminal via a wireless communication line.

  The present invention can be used for a car navigation system and the like.

FIG. 1 is a configuration diagram showing a car navigation system according to Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram showing the contents stored in the storage device in FIG. FIG. 3 is a diagram for explaining the relationship between roads in a certain area, links, and nodes. FIG. 4 is a block diagram showing functions implemented in the car navigation system by the CPU in FIG. 1 executing the guide route generation program. FIG. 5 is a block diagram showing functions realized in the car navigation system by the CPU in FIG. 1 executing the route guidance program. FIG. 6 is a flowchart showing the overall operation during the route search of the car navigation system shown in FIG. FIG. 7 is a flowchart showing detailed steps of the route search processing for the first section in FIG. FIG. 8 is a flowchart showing detailed steps of the route search processing for the next section in FIG. FIG. 9 is a block diagram showing functions realized when searching for a guidance route in the car navigation system according to Embodiment 2 of the present invention. FIG. 10 is a flowchart showing detailed steps of a route search process for the next section in the car navigation system according to the second embodiment.

Explanation of symbols

15 Storage device (cost information storage means, priority coefficient storage means, subordinate coefficient storage means)
42, 62 Cost calculation condition setting section (determination means)
44, 63 Cost calculation part (cost calculation means)
45 Guide route selector (selection means)
56 Route Guide (Route Guide)

Claims (10)

When searching for a guide route from the departure point to the destination via the passing point, when searching for a route from the passing point to the next passing point or the route to the destination, the passage in the route to the passing point In a guide route search device that performs straight road priority control that gives priority to a link and / or a node ahead in the direction of travel to a point,
A judging means for judging whether or not it is possible to make a U-turn at the passing point;
Cost information storage means for storing cost information of links and / or nodes selected as routes;
If it is determined by the determination means that it is possible to make a U-turn at the passing point, the straight road priority control is prohibited and the cost of the link and / or node stored in the cost information storage means A cost calculating means for calculating the cost of the route searched for the section from the passing point to the next passing point or the destination using the information;
Using the cost calculated by the cost calculating means, the costs of a plurality of routes searched for the section from the passing point to the next passing point or the destination are compared, and one route is selected from the plurality of routes. Selecting means as a guide route of a section from the passing point to the next passing point or destination,
A guide route search device characterized by comprising: When searching for a guide route from a departure point to a destination via a passing point, when searching for a route from the passing point to the next passing point or the destination, it is possible to make a U-turn at the passing point. A determination means for determining whether or not
Cost information storage means for storing cost information of links and / or nodes selected as routes;
If it is determined by the determining means that it is possible to make a U-turn at the passing point, the cost information of the link and / or node stored in the cost information storing means is used to reach the passing point. Based on the approach direction to the passing point in the route of the section, the cost information is adjusted so that the route returning in the reverse direction of the approach direction is more easily selected than the route traveling forward in the approach direction. A cost calculating means for calculating a cost of a route searched for a section from a passing point to a next passing point or a destination;
Using the cost calculated by the cost calculating means, the costs of a plurality of routes searched for the section from the passing point to the next passing point or the destination are compared, and one route is selected from the plurality of routes. Selecting means as a guide route of a section from the passing point to the next passing point or destination,
A guide route search device characterized by comprising: The cost calculation means includes the cost information as cost information of a link and / or a node that is a route returning in the reverse direction with reference to the approach direction to the passing point in the route of the section from the passing point to the passing point. Using the cost information having a value smaller than the cost information of that link and / or node stored in the storage means, calculating the cost of the searched route;
The selection means selects a route with the lowest cost as a guide route for a section from the passing point to a next passing point or a destination,
The guide route search device according to claim 2. A link and / or node that becomes a path returning in the reverse direction based on the approach direction to the passing point in the path of the section to the passing point from the cost information of the link and / or node stored in the cost information storage unit When obtaining the cost information, there is a priority coefficient storage means for storing a U-turn priority coefficient that reduces the value of the cost information,
The cost calculating means, when the judging means judges that it is possible to make a U-turn at the passing point, the link and / or the node serving as a path returning in the direction opposite to the approaching direction to the passing point The cost information of the searched route is calculated using the cost information obtained by applying the U-turn priority coefficient to the cost information of
The selecting means selects a route with the lowest cost as a guide route of a section from the passing point to a next passing point or a destination;
The guide route search device according to claim 2.   The cost calculation means includes cost information of a plurality of links within a predetermined number of ranges counted from the passing point, cost information of a plurality of links within a predetermined distance range from the passing point, and from the passing point to the main road. The U-turn priority coefficient is added to the cost information of a plurality of links until the return or the cost information of the links from the first link on the route returning from the passing point to the link before the link of a different road type. The guidance route search device according to claim 4, which is applied.   6. The guidance according to claim 5, wherein the cost calculation means switches the number or range of links to which the U-turn priority coefficient is applied according to a distance from the passing point to a next passing point or a destination. Route search device.   The determination means is provided when there is a facility of a predetermined genre that can be estimated that there is a parking lot or an attached parking lot at the passing point, or a parking lot on the site as information on the facility at the passing point. Alternatively, the guidance route search device according to any one of claims 1 to 6, wherein when a round road in the site is obtained, it is determined that a U-turn is possible at the passing point. The determination means is, when there is a facility of a predetermined genre that can be estimated that there is a parking lot or an attached parking lot at the passing point, or a parking lot on the site as information on the facility at the passing point or When the road around the site is available, and
When the road in front of the facility at the passing point can travel in the direction of returning to the reverse direction based on the approach direction to the passing point in the route of the section to the passing point,
The guidance route search device according to any one of claims 1 to 6, wherein it is determined that a U-turn is possible at the passing point. When searching for a guide route from a departure point to a destination via a passing point, when searching for a route from the passing point to the next passing point or to the destination, it is possible to make a U-turn at the passing point. Determining whether there is,
If it is determined that it is possible to make a U-turn at the passing point, a straight road priority is given to the link and / or node ahead of the passing direction to the passing point in the route of the section to the passing point. The step of calculating the cost of the route searched for the section from the passing point to the next passing point or the destination using the link and / or node cost information stored in the cost information storing means while prohibiting the control. When,
Using the calculated cost, the costs of a plurality of routes searched for the section from the passing point to the next passing point or the destination are compared, and one route is selected from the plurality of routes as the passing point. Selecting as a guide route for a section from to the next passing point or destination,
A guide route search method characterized by comprising: When searching for a guide route from a departure point to a destination via a passing point, when searching for a route from the passing point to the next passing point or the destination, it is possible to make a U-turn at the passing point. A step of determining whether or not
If it is determined that it is possible to make a U-turn at the passing point, the cost information of the section to the passing point is used by using the cost information of the link and / or node stored in the cost information storage unit. Based on the approach direction to the passing point, the cost information is adjusted so that a route returning in the reverse direction of the approach direction is more easily selected than a route traveling forward in the approach direction. Calculating the cost of the route searched for the way to the passing point or destination;
Using the calculated cost, the costs of a plurality of routes searched for the section from the passing point to the next passing point or the destination are compared, and one route is selected from the plurality of routes as the passing point. Selecting as a guide route for a section from to the next passing point or destination,
A guide route search method characterized by comprising:

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