JP2006119078A - Guide path search system and guide path search method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To select proper path in the case that destination point locates at a very close distance behind the present location. <P>SOLUTION: A decision means 41 of a guide path search system decides whether the position relation between the terminal destination point of the path search or path locations is shorter than a specific distance behind the present location. When the terminal point of the path search is decided as being set shorter than the specific distance behind the initial point of the path search by the decision means 41, a cost calculating means 43 lowers the value of cost information on the link and/or node in the progressing direction front at the present location, inhibits along-a-road priority control, in which the link and/or node in the progressing direction front is given priority, and calculates the cost of the searched route by using cost information of the link and/or node stored in a cost information memory means 15. A selecting means 44 selects one path from among a plurality of routes as a guide path 48, by using the cost calculated with the cost calculating means 43 and comparing the costs of searched 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 vehicle guidance device. This vehicle guidance device restricts selection of a link that is in a direction opposite to the traveling direction of the vehicle during the route search as a route with respect to the link where the vehicle is present during the route search. Specifically, a predetermined value is added to the cost of the U-turn side link, or a coefficient is multiplied.

  Further, in Patent Document 1, by setting the change value of the link cost to an appropriate value, the distance to the next intersection node on the traveling direction side of the vehicle is very large in an urban area or the like, or the traveling direction reaches a dead end. In such a case, the cost of a route including a link making a U-turn is relatively low, and a route including a link making a U-turn can be obtained as a search result. .

JP-A-8-159793 (claims, detailed description of the invention, paragraph 0031, paragraph 0032, etc.)

  In the conventional guidance route searching device, the conventional vehicle guidance device described in Patent Document 1 adds a predetermined value to the cost of the link on the U-turn side or multiplies a coefficient when searching for a route. Calculate the cost of each candidate route searched under conditions such as U-turn regulation, road priority (reducing the cost of the direction of the vehicle, that is, the link ahead in the direction of travel, etc.) Selected as a guide route.

  As a result, when the destination is prioritized, when the destination is set, the traveling direction of the host vehicle is determined, and it is easy to select the route toward the destination after proceeding along the traveling direction forward. In other words, it is not necessary to search for a U-turn route at the current location.

  However, when the road priority conditions are set in this way, for example, the destination is set at a close distance behind the current location, and it is clearly the earliest to make a U-turn and head to the destination. However, after going straight along the road, the route that deviates from the road toward the destination is selected as the guide route.

  An object of the present invention is to obtain a guidance route search device and a guidance route search method in which an appropriate route is selected when a destination is at a close distance behind the current location.

  The route searching apparatus according to the present invention prioritizes a link and / or a node ahead in the traveling direction by lowering the cost information value of the link and / or node ahead in the traveling direction at the present location in the route search. In the guidance route search device that executes the priority control, the relative positional relationship of the destination or waypoint that is the end point of the route search is based on the current location as the starting point and the current traveling direction at the current location A determination means for determining whether or not the distance is equal to or less than a predetermined distance; a cost information storage means for storing cost information of a link and / or a node selected as a route from the start point to the end point of the route search; and a route by the determination means If it is determined that the end point of the search is set to be equal to or less than the predetermined distance behind the starting point of the route search, the road priority control is prohibited and the cost information A cost calculation unit that calculates the cost of the searched route using the cost information of the link and / or node stored in the storage unit, and a plurality of routes searched using the cost calculated by the cost calculation unit And a selection means for selecting one route as a guide route from among the plurality of routes.

  Another guidance route search device according to the present invention is based on the current location as a starting point of the route search and the current traveling direction at the current location as a reference, the relative positional relationship of the destination or waypoint as the end point of the route search, Judgment means for judging whether or not the distance is below a predetermined distance behind the current location; Cost information storage means for storing cost information of links and / or nodes selected as a route from the starting point to the end point of the route search; When it is determined by the means that the end point of the route search is set to be equal to or less than a predetermined distance behind the start point of the route search, the progress is made using the cost information of each link and / or node stored in the cost information storage means. The cost information is adjusted to calculate the cost of the searched route so that the route going backward in the direction of travel is easier to select than the route going forward in the direction. A calculation unit, and a selection unit that compares costs of a plurality of searched routes using the cost calculated by the cost calculation unit and selects one route as a guide route from the plurality of routes. Is.

  In another guide route search apparatus according to the present invention, in addition to the configuration of the invention described above, the cost calculation means is stored in the cost information storage means as the cost information of the link and / or the node that is behind the current direction in the traveling direction. The cost information having a value smaller than the cost information of the link and / or the node is calculated to calculate the cost of the searched route, and the selection means selects the route having the lowest cost as the guide route. .

  In addition to the configuration of each invention described above, another guide route search device according to the present invention uses the cost information of the link or node stored in the cost information storage means, and the cost of the link or node that is behind the current direction from the current location. When obtaining information, the apparatus has priority coefficient storage means for storing a U-turn priority coefficient that reduces the value of cost information, and the cost calculation means uses a determination means to determine that the end point of the route search is a predetermined distance behind the starting point of the route search. When it is determined that the following is set, the U-turn priority coefficient is applied to the cost information of the link and / or node stored in the cost information storage means for the link and / or node that is behind in the traveling direction from the current location. The cost information of the searched route is calculated using the calculated cost information, and the selection means selects the route with the lowest cost as the guide route. It is intended.

  In another guide route search apparatus according to the present invention, in addition to the configuration of each of the above-described inventions, the cost calculation unit stores the cost information in the cost information storage unit as the cost information of the link and / or node that is forward in the traveling direction from the current location. The cost information having a value larger than the cost information of the link and / or node to be calculated is used to calculate the cost of the searched route, and the selection means selects the route with the lowest cost as the guide route. is there.

  In addition to the configuration of each invention described above, the other guide route search device according to the present invention uses the cost information of the link or node stored in the cost information storage means to determine the cost of the link or node forward in the traveling direction from the current location. When obtaining information, there is a subordinate coefficient storage means for storing the subordinate coefficient that increases the value of the cost information, and the cost calculating means uses the judging means to determine the predetermined distance behind the starting point of the route search by the determining means. If it is determined that the link or node is forward in the direction of travel from the current location, the cost information obtained by applying the subordination coefficient to the cost information of the link or node stored in the cost information storage means is obtained. The cost of the searched route is calculated and the selection means selects the route with the lowest cost as the guide route.

  The guide route search method according to the present invention uses a current position as a starting point and a current traveling direction at the current location as a reference, so that the relative positional relationship between a destination or a stop point as a route search end point is a predetermined position behind the current location. A step of determining whether or not the distance is equal to or less than the distance, and if it is determined that the end point of the route search is set to be equal to or less than a predetermined distance behind the start point of the route search, By lowering the value of the cost information of the node and prohibiting the priority control that gives priority to the link and / or node ahead in the traveling direction, the cost information of the link and / or node stored in the cost information storage means is used, The cost of the searched route is calculated, and the calculated cost is used to compare the costs of the plurality of searched routes, and from among the plurality of routes. Selecting One of the route as the guidance route, and has a.

  Another guide route search method according to the present invention is based on the current location that is the starting point of the route search and the current traveling direction at the current location as a reference, and the relative positional relationship between the destination or the waypoint that is the end point of the route search is The step of determining whether or not the distance is less than or equal to the predetermined distance behind the current location, and if it is determined that the end point of the route search is set to be equal to or less than the predetermined distance behind the starting point of the route search, the cost information storage means stores The cost information of the searched route is adjusted by using the cost information of the link and / or the node to adjust the cost information so that the route traveling backward in the traveling direction is more easily selected than the route traveling forward in the traveling direction. The calculating step and the calculated cost are used to compare the costs of a plurality of searched routes, and one route is selected as the guide route from the plurality of routes. And, those having a.

  In the present invention, an appropriate route is selected when the destination is at a close distance behind the current location.

  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 a guide route of a vehicle from a current location to a destination or waypoint, and guides the route so that the vehicle moves along the guide route.

  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 a name of a building, a store, a facility, etc. at the point, position information of the point, and the like. 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.

  In the region shown in FIG. 3A, a first national road 31 and a first local road 32 run in parallel along the horizontal direction of the figure. A second national road 33 and a second local road 34 run vertically in the figure. The second national road 33 intersects the first national road 31 and the first local road 32. The second local road 34 intersects the first local road 32 and hits 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 second national road 33 and the first national road 31, an intersection 37 between the second national road 33 and the first local road 32, and a second local road 34 and the first national road 31. It is provided in association with an intersection (around the second local road 34) 38 and an intersection 39 between the second local road 34 and the first local road 32. There are a total of four nodes in this region.

  In addition, a link is provided for each section between intersections in association with roads in such areas. Specifically, the first national road 31 along the horizontal direction of the figure has two nodes. Therefore, this two-lane road (4 lanes in total) is composed of six links. Similarly, the first local road 32 is composed of six links. The second national road 33 is composed of six links. The second local road 34 is composed of four links. There are a total of 22 links in this area.

  The link data group 25 has a plurality of records. Each record of the link data group 25 has one link data. Each record includes traffic regulation information regarding the link, distance of the link, cost information passing through the link, an identification number unique to the link, 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 road priority coefficient.

  The traffic congestion coefficient is a coefficient that is multiplied by cost information of links and nodes that are congested. The road 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 the traveling direction of the vehicle and the traveling lane are known in advance, the road or the lane in the traveling direction is relatively easily selected as a guide route compared to other roads. . The road priority coefficient is a coefficient multiplied by the cost information of the road link. The road priority coefficient has a value less than one. Thereby, the passing cost of the road in the traveling direction of the vehicle 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. As the CPU 2 in FIG. 1 executes the guidance route generation program 21, a cost calculation condition setting unit 41 as a determination unit, a candidate route generation unit 42, a cost calculation unit 43 as a cost calculation unit, and a selection unit The guide route selection unit 44 is realized.

  Based on the cost calculation condition list 27, the cost calculation condition setting unit 41 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 road priority coefficient in a situation where a search is made with road priority.

  The candidate route generation unit 42 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 42 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 current location or departure location of the vehicle is used as a starting point for route search. The destination 35 or the waypoint is used as the end point of the route search.

  The cost calculation unit 43 calculates the cost of the candidate route searched by the candidate route generation unit 42.

  The guide route selection unit 44 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, the search process for the guide route 48 will be described with reference to FIG.

  Further, in the following description, as a specific example of the processing for generating the guide route 48, as indicated by the own vehicle position mark 40 in FIG. 3A, the vehicle is the second national road 33 and the second local road 34. It is assumed that the vehicle is traveling on the first national highway 31 between. The location where the vehicle position mark 40 is present is the current location.

  Further, a case will be described as an example where the destination 35 is set on the first national road 31 at a distance behind the vehicle in the traveling direction and within 2 km. For the destination 35, for example, the point data is displayed on the liquid crystal device 11, and the point selected based on the operation position information output by the touch panel 12 in the display may be set as the destination 35.

  The location information 49 of the vehicle position mark 40 (current location) and the location information 50 of the destination 35 are stored in the storage device 15.

  In addition to the position information 49 of the vehicle position mark 40 (current location) and the position information 50 of the destination 35, the storage device 15 includes traffic information or traffic regulations included in the traffic information received by the VICS receiver 14. Information (congestion / traffic regulation information 51) is stored.

  For example, position information of the GPS receiver 13 generated by the GPS receiver 13 can be used as the position information 49 of the current location of the vehicle in the route search. The current location of the host vehicle may be, for example, a position on a link specified based on the position information of the GPS receiver 13. In this case, the current location of the subject vehicle is, for example, the location where the perpendicular and the link intersect when the perpendicular is dropped from the position information of the GPS receiver 13 to the link. When the link where the vehicle is present is specified in this way, as shown in FIG. 3B, the vehicle position mark 40 is displayed at the corresponding point on the matching link. become.

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

  When a search start instruction is issued from the touch panel 12 or the like along with the selection of the destination 35, the cost calculation condition setting unit 41 starts the process for setting the cost calculation condition 46. First, the cost calculation condition setting unit 41 selects a current location stored in the storage device 15 as a search starting point, and selects a destination 35 or waypoint stored in the storage device 15 as an end point of the search. .

  When the search start point and end point are selected, the cost calculation condition setting unit 41 starts setting the route search condition. The cost calculation condition setting unit 41 causes the storage device 15 to store the congestion coefficient stored in the cost calculation condition list 27 as the cost calculation condition 46.

  The cost calculation condition setting unit 41 also calculates a straight line distance from the search start point to the end point. The cost calculation condition setting unit 41 determines whether or not the linear distance from the search start point to the end point is 2 km or less (step ST1).

  When the linear distance from the search start point to the end point is longer than 2 km, the cost calculation condition setting unit 41 reads the road priority coefficient from the cost calculation condition list 27 and stores the read road priority coefficient as the cost calculation condition 46 as a storage device. 15 (step ST2).

  When the linear distance from the starting point to the ending point of the search is 2 km or less, the cost calculation condition setting unit 41 uses the traveling direction of the host vehicle as a reference to determine the angle of the direction from the starting point of the search to the destination 35 (hereinafter referred to as the target). It is called the local angle.) As the traveling direction of the own vehicle, the direction of the link that the own vehicle is matched to, whether it is the traveling direction when the vehicle is stopped or the direction specified based on the positional information from the GPS receiver 13 at that time It may be. Then, the cost calculation condition setting unit 41 determines whether or not the target local angle is within the range of 90 degrees to 270 degrees (step ST3).

  When the target local angle is smaller than 90 degrees or larger than 270 degrees, the cost calculation condition setting unit 41 reads the road priority coefficient from the cost calculation condition list 27, and uses the read road priority coefficient as the cost calculation condition 46. Is stored in the storage device 15 (step ST2).

  Through the above setting process of the cost calculation condition 46, various coefficients such as the road priority coefficient are stored in the storage device 15 as the cost calculation condition 46. If the distance from the current position of the vehicle to the destination 35 is 2 km or less and the destination local angle is 90 degrees or more and 270 degrees or less, the road priority coefficient is set as the cost calculation condition 46 Not. When the positional relationship between the starting point and the ending point of the search is any other positional relationship, the road priority coefficient is set as the cost calculation condition 46.

  For example, in FIG. 3 (A), the half-circle hatched area is a distance of 2 km or less from the current position of the vehicle and the target local angle is 90 degrees or more and 270 degrees or less. It becomes. The destination 35 in FIG. 3 (A) is within the semi-circle hatched portion. In this case, the cost calculation condition setting unit 41 does not set the road priority coefficient as the cost calculation condition 46.

  When the setting process of the cost calculation condition 46 is completed, the cost calculation condition setting unit 41 instructs the candidate route generation unit 42 to generate a candidate route.

  Note that the cost calculation condition setting unit 41 may instruct the candidate route generation unit 42 to generate a candidate route before starting the setting process of the cost calculation condition 46. For example, when there is a search start instruction associated with reception of traffic jam information from the VICS receiver 14, the cost calculation condition setting unit 41 does not perform the setting process of the cost calculation condition 46 and sends it to the candidate route generation unit 42. You may make it instruct | indicate the production | generation of a candidate path | route. The cost calculation condition setting unit 41 detects that there is little change in the position information from the GPS receiver 13, and the candidate route generation unit 42 is voluntarily sent to the candidate route generation unit 42 without setting the cost calculation condition 46. The generation may be instructed.

  Candidate route generation unit 42 generates a candidate route using link data group 25 and node data group 26 (step ST4). Specifically, the candidate route generation unit 42 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 42 generates a chain of links from the starting point to the end point of this search as a candidate route.

  If the starting point (current location) 40 and the end point (destination 35) of the search are in a positional relationship as shown in FIG. 3A, the candidate route generation unit 42, for example, the link L1 in which the vehicle is map-matched As a first link, as shown in FIG. 3B, a candidate route “starting point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point” is generated. This candidate route is a route that travels straight in the traveling direction of the vehicle and then travels to the end point. This candidate route does not make a U-turn in the middle.

  Further, for example, as shown in FIG. 3 (B), the candidate route generation unit 42 uses the link L6 on the opposite lane on the same road as the link with which the vehicle is map-matched as the first link, as shown in FIG. → N4 → L5 → end point ”is generated. This candidate route is a route toward the end point after making a U-turn at the current location of the vehicle.

  In this candidate route generation process, the candidate route generation unit 42 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. 3A, the candidate route generation unit 42 determines that “start point → L6 → N4 → L5 → The candidate route “end point” is not generated. In addition, for example, if there is a right turn prohibition time zone at the intersection 38 on the second local road 34, and the time zone falls within that time zone, the candidate route generation unit 42 selects “start point → L1 → N1 → L2 → N2 → The candidate route “L3 → N3 → L4 → N4 → L5 → end point” is not generated.

  The candidate route generation unit 42 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 43 calculates the cost of each candidate route (step ST5).

  The cost calculation unit 43 first calculates an individual passage cost for each link and each node included in the candidate route.

  At this time, for example, when a road priority coefficient is set in the cost calculation condition 46, the cost calculation unit 43 adds the cost information in the link data group 25 or the node data group 26 of the link or node corresponding to the condition to the cost information. The coefficient is multiplied and the result of the operation is used as the individual passing cost of the link or node. Thereby, the passage cost of the road corresponding to a road becomes low.

  Further, for the link of the road where the traffic jam occurs in the traffic jam / traffic regulation information 51, the cost calculation unit 43 multiplies the traffic jam coefficient for the link. 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 43 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 the link or node 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 43 adds all the individual passage costs and sets the calculation result as the cost of the candidate route. Note that the cost calculation unit 43 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.

  Specifically, for example, in the case of the above candidate route “start point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point”, the cost calculation unit 43 includes the link L1, the node N1, the link The individual passage costs of L2, node N2, link L3, node N3, link L4, node N4, and link L5 are calculated, and a value obtained by adding them is calculated as the cost of the candidate route.

  In the case of FIG. 3A, the destination 35 is in a semicircle hatching. Therefore, no road priority coefficient is set as the cost calculation condition 46. Therefore, the cost calculation unit 43 uses the cost information stored in the link data group 25 and the node data group 26 as the individual passing costs of the link L1 and the node N1 as they are as the individual passing costs of the link or node. The cost of the candidate route “starting point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point” is calculated.

  In addition, for example, the cost calculation unit 43 calculates the individual passage costs of each of the link L6, the node N4, and the link L5 and adds them to the candidate route “start point → L6 → N4 → L5 → end point”. Calculate as cost.

  When the cost of each candidate route stored in the storage device 15 is calculated, the guide route selection unit 44 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 ST6).

  In the case of FIG. 3 (A), the destination 35 is in the semicircle hatching. Therefore, the cost of each candidate route is calculated as the cost calculation condition 46 without setting the road priority coefficient. Therefore, the guidance route selection unit 44 is referred to as “start point → L 1 → N 1 → L 2 → N 2 → L 3 → N 3 → L 4 → N 4 → L 5 → end point” generated based on the cost information of the link data group 25 and the node data group 26. The cost of the candidate route is compared with the cost of the candidate route “start point → L6 → N4 → L5 → end point”.

  The cost of the candidate route “start point → L6 → N4 → L5 → end point” is “start point → L1 → N1 → L2 → N2 → L3 → N3 → unless a road priority coefficient or the like is set in the cost calculation condition 46. It is lower than the cost of the candidate route “L4 → N4 → L5 → end point”. Therefore, the guide route selection unit 44 selects a candidate route “starting point → L6 → N4 → L5 → ending point” as the guide route 48.

  The guide route selection unit 44 stores the selected candidate route in the storage device 15 as the guide route 48.

  As a result of the search processing for the guide route 48 described above, the storage device 15 stores the guide route 48 from the search start point to the end point. In the case of FIG. 3A, a route “starting point → L 6 → N 4 → L 5 → ending point” is stored in the storage device 15 as the guide route 48. This route “starting point → L6 → N4 → L5 → ending point” is a route heading to the ending point after making a U-turn at the current location of the vehicle.

  If the destination 35 in FIG. 3 is located outside of the semicircle, a candidate “starting point → L6 → N4 → L5 → ending point” is set by setting a road priority coefficient as the cost calculation condition 46. When the cost of the route is higher than the cost of the candidate route “start point → L 1 → N 1 → L 2 → N 2 → L 3 → N 3 → L 4 → N 4 → L 5 → end point”, the storage device 15 stores “start point → The route “L1-> N1-> L2-> N2-> L3-> N3-> L4-> N4-> L5-> end point" is stored. This route is a route toward the end point without making a U-turn after going straight in the direction of travel from the current location of the vehicle.

  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 40. 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.

  FIG. 7 is a display screen showing an example of a map and a guide route displayed on the liquid crystal device 11. On the display screen, a vehicle position mark 40, a route to be guided, a map, and a destination 35 are displayed. Further, the liquid crystal device 11 displays a guide route 61 that makes a U-turn from the current location where the host vehicle position mark 40 is located to the destination 35.

  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 host vehicle specified by the position information from the GPS receiver 13 has moved from the position of the host vehicle position mark 40 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.

  If the previous route “start point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point” is a guide route, a route 62 indicated by a dotted line in FIG. Is displayed.

  In addition, after reading the position information from the GPS receiver 13, the route guide unit 56 may generate new display data without determining the movement of the vehicle position. 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 40 moves along the guide route 48 displayed on the liquid crystal device 11, the vehicle can move from the current location or the like to the destination 35 or the waypoint. Move to.

  As described above, in the car navigation system according to the first embodiment, the linear distance from the current location as the search starting point to the end point is a distance of 2 km or less, and the target local angle for viewing the end point from the start point is 90. If it is greater than or equal to 270 degrees and less than or equal to 270 degrees, it is determined that the end point of the search has been set to a close distance behind the current location. As a result, the car navigation system determines whether or not the end point of the search has been set to a close distance behind the current location by a simple calculation process before searching for a candidate route from the current location that is the starting point of the search to the end point. Can be judged.

  Further, in the car navigation system according to the first embodiment, when the end point of the search is set to be equal to or less than a predetermined distance behind the current location, the link and node stored in the link data group 25 and the node data group 26 are stored. The cost information is added as it is, and the cost of each candidate route is calculated. That is, the cost calculation unit 43 does not calculate the cost of each candidate route under the road priority condition.

  Therefore, when the car navigation system determines that the end point of the search is set to be equal to or less than the predetermined distance behind the current location, the car navigation system can generate a route that makes the vehicle make a U-turn as the guide route 48.

  As a result, in the case where the car navigation system can reach the destination 35 clearly earlier when the U-turn is made so as to meet the above-described conditions, It is possible to guide a route that makes a U-turn that can reach the destination 35 earlier than the guide route 48 in the case of searching.

  Further, the car navigation system according to the first embodiment determines whether or not the end point of the search is set to be equal to or less than a predetermined distance behind the current location, and determines whether or not to use the road priority coefficient for cost calculation. I have control. The cost calculation unit 43 calculates the cost of each candidate route under the set conditions. Therefore, for example, even when it is determined that the end point of the search is set to a close distance behind the current location, a route that travels along the road toward the destination can be selected.

  In the first embodiment, the current location is used as a starting point for route search. As a starting point of the search, in addition to the current location, a transit location or the like can be selected as the departure location. The car navigation system may search for a route from a waypoint to the destination 35 or another waypoint. Therefore, the cost calculation condition setting unit 41 determines, for example, whether or not the starting point of the search is the current location, for example, prior to the determination of the linear distance from the starting point to the end point of the search. The determination of the linear distance from the starting point to the end point of the search and the subsequent processing may be performed. As a result, a route search from the current location and a route search from the transit location are distinguished, and for example, a search is performed such that the linear distance from the transit location that is different from the current location to the destination 35 is 2 km or less. In some cases, it is possible to prevent a route search from being performed under a search condition in which the road priority is canceled.

Embodiment 2. FIG.
FIG. 8 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 71 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 is, for example, when a traveling direction or a driving lane of a vehicle is known in advance, a road or lane traveling in the opposite direction to the traveling direction is relatively selected as a guide route 48 compared to other roads. It is easy to be done. The U-turn priority coefficient is a coefficient that is multiplied by the cost information of the link that is in the opposite direction to the traveling direction. The U-turn priority coefficient has a value smaller than 1. Thereby, the cost of passing the road in the direction opposite to the traveling direction of the vehicle can be reduced.

  Based on the cost calculation condition list 71, the cost calculation condition setting unit 72 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 72 functions as a determination unit.

  The cost calculation unit 73 calculates the cost of each candidate route stored in the storage device 15 as the candidate route list 47. The cost calculation unit 73 functions as a cost calculation unit.

  The other constituent elements shown in FIG. 8 have the same functions as those of the constituent elements having the same names 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 72 and the cost calculation unit 73 are realized together with the candidate route generation unit 42 and the guide route selection unit 44 by the CPU 2 executing the guide route generation program stored in the storage device 15. Is done.

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

  FIG. 9 is a flowchart showing an operation during route search of the car navigation system shown in FIG.

  The cost calculation condition setting unit 72 starts to set the cost calculation condition 46 after selecting the current location as the search start point and the destination 35 as the end point based on the search start instruction from the touch panel 12 or the like. The cost calculation condition setting unit 72 stores the congestion coefficient stored in the cost calculation condition list 71 in the storage device 15 as the cost calculation condition 46.

  The cost calculation condition setting unit 72 determines whether or not the straight line distance from the search start point to the end point is 2 km or less (step ST1). If the straight line distance from the search start point to the end point is longer than 2 km, the cost calculation condition list The road priority coefficient stored in 71 is stored in the storage device 15 as the cost calculation condition 46 (step ST2).

  If the straight line distance from the starting point to the ending point of the search is 2 km or less, the cost calculation condition setting unit 72 determines whether or not the target local angle is within the range of 90 degrees to 270 degrees (step ST3). Is smaller than 90 degrees or larger than 270 degrees, the road priority coefficient is stored in the storage device 15 as the cost calculation condition 46 (step ST2).

  When the target local angle is within the range of 90 degrees to 270 degrees, the cost calculation condition setting unit 72 stores the U-turn priority coefficient stored in the cost calculation condition list 71 in the storage device 15 as the cost calculation condition 46. (Step ST11).

  When the destination 35 is in the hatched portion of FIG. 3A by the above setting process of the cost calculation condition 46, the cost calculation condition setting unit 72 sets the road priority coefficient as the cost calculation condition 46. Without setting, the congestion coefficient and U-turn priority coefficient are set. When the destination 35 is in any other place, the cost calculation condition setting unit 72 sets a traffic congestion coefficient and a road priority coefficient as the cost calculation condition 46.

  When the setting process of the cost calculation condition 46 is completed, the cost calculation condition setting unit 72 instructs the candidate route generation unit 42 to generate a candidate route. Candidate route generation unit 42 generates a candidate route using link data group 25 and node data group 26 (step ST4). When the candidate route is stored in the storage device 15, the cost calculation unit 73 calculates the cost of each candidate route (step ST5). When the cost of each candidate route stored in the storage device 15 is calculated, the guide route selection unit 44 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 ST6). The guide route selection unit 44 stores the selected candidate route in the storage device 15 as the guide route 48.

  By the way, when the U-turn priority coefficient is set as the cost calculation condition 46, the cost calculation unit 73 determines that “start point → L6 → N4 → L5 → When calculating the cost of the candidate route “end point”, the individual passage cost is calculated as follows. That is, the cost calculation unit 73 multiplies the cost information stored in the link data group for the link L6 by the U-turn priority coefficient, and sets the calculation result as an individual passage cost for the link L6. The cost calculation unit 73 multiplies the cost information stored in the node data group for the node N4 by the U-turn priority coefficient, and sets the calculation result as the individual passing cost of the node N4. The cost calculation unit 73 multiplies the cost information stored in the link data group for the link L5 by the U-turn priority coefficient, and sets the calculation result as the individual passage cost of the link L5.

  Therefore, the cost of the candidate route “starting point → L6 → N4 → L5 → ending point” is compared with the case where the cost information stored in the link data group 25 and the node data group 26 is used as the individual passing costs as they are. , Get smaller. The guide route selection unit 44 then reduces the cost of the reduced candidate route “start point → L6 → N4 → L5 → end point” and “start point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → The cost of the candidate route “L5 → end point” is compared.

  As a result, for example, when the cost information stored in the link data group 25 and the node data group 26 is directly calculated as individual passing costs, the cost of the candidate route “start point → L6 → N4 → L5 → end point” is reduced. Even if it is higher than the cost of the candidate route “start point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point”, the “start point → L6 → N4 → L5 → end point” , The candidate route “start point → L6 → N4 → L5 → end point” can be easily selected as the guide route.

  As described above, in the car navigation system according to the second embodiment, the linear distance from the current location as the search starting point to the end point is 2 km or less, and the target local angle for viewing the end point from the start point is 90. If it is greater than or equal to 270 degrees and less than or equal to 270 degrees, it is determined that the end point of the search has been set to a close distance behind the current location, and the cost of each candidate route is calculated under the condition of U-turn priority.

  Accordingly, when the car navigation system determines that the end point of the search is set to be equal to or less than the predetermined distance behind the current location, the cost of the route for making the vehicle U-turn is relatively lower than the cost of the other routes. A route for making a U-turn of the vehicle is easily generated as the guide route 48.

  As a result, in the case where the car navigation system can reach the destination 35 clearly earlier when the U-turn is made so as to meet the above-described conditions, It is possible to guide a route that makes a U-turn that can reach the destination 35 earlier than the guide route 48 in the case of searching.

Embodiment 3 FIG.
FIG. 10 is a block diagram showing functions realized when searching for a guidance route in the car navigation system according to Embodiment 3 of the present invention.

  The cost calculation condition list 81 stored in the storage device 15 stores various coefficients such as a congestion coefficient, a road priority coefficient, and a road subordinate coefficient.

  Road inferiority means that, for example, when the traveling direction of a vehicle and the traveling lane are known in advance, the road or lane traveling in the traveling direction is relatively difficult to select as the guide route 48 compared to other roads. It is. The road subordination coefficient is a coefficient multiplied by the cost information of the link in the traveling direction. The roadside subordination coefficient has a value greater than one. Thereby, the passage cost of the road to the advancing direction of a vehicle can be raised.

  Based on the cost calculation condition list 81, the cost calculation condition setting unit 82 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 road subordination coefficient under a situation of searching for road subordination. The cost calculation condition setting unit 82 functions as a determination unit.

  The cost calculation unit 83 calculates the cost of each candidate route stored in the storage device 15 as the candidate route list 47. The cost calculation unit 83 functions as a cost calculation unit.

  The other constituent elements shown in FIG. 8 have the same functions as those of the constituent elements having the same names 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. In the car navigation system according to the third 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 82 and the cost calculation unit 83 are realized together with the candidate route generation unit 42 and the guide route selection unit 44 by the CPU 2 executing the guide route generation program stored in the storage device 15. Is done.

  Next, the operation of the car navigation system according to Embodiment 3 having the above configuration will be described.

  FIG. 11 is a flowchart showing an operation during route search of the car navigation system shown in FIG.

  The cost calculation condition setting unit 82 starts setting the cost calculation condition 46 after selecting the current location as the search start point and the destination 35 as the end point based on the search start instruction from the touch panel 12 or the like. The cost calculation condition setting unit 82 causes the storage device 15 to store the congestion coefficient stored in the cost calculation condition list 81 as the cost calculation condition 46.

  The cost calculation condition setting unit 82 determines whether or not the straight line distance from the search start point to the end point is 2 km or less (step ST1). If the straight line distance from the search start point to the end point is longer than 2 km, the cost calculation condition list The road priority coefficient stored in 81 is stored in the storage device 15 as the cost calculation condition 46 (step ST2).

  When the straight line distance from the starting point to the ending point of the search is 2 km or less, the cost calculation condition setting unit 82 determines whether or not the target local angle is within the range of 90 degrees to 270 degrees (step ST3). Is smaller than 90 degrees or larger than 270 degrees, the road priority coefficient is stored in the storage device 15 as the cost calculation condition 46 (step ST2).

  When the target local angle is within the range of 90 degrees to 270 degrees, the cost calculation condition setting unit 82 stores the road subordination coefficient stored in the cost calculation condition list 81 as the cost calculation condition 46 in the storage device 15. (Step ST21).

  When the destination 35 is in the hatched portion of FIG. 3A by the above setting process of the cost calculation condition 46, the cost calculation condition setting unit 82 sets the road priority coefficient as the cost calculation condition 46. Set the traffic congestion coefficient and road subordination coefficient. When the destination 35 is in any other place, the cost calculation condition setting unit 82 sets a traffic congestion coefficient and a road priority coefficient as the cost calculation condition 46.

  When the setting process of the cost calculation condition 46 is completed, the cost calculation condition setting unit 82 instructs the candidate route generation unit 42 to generate a candidate route. Candidate route generation unit 42 generates a candidate route using link data group 25 and node data group 26 (step ST4). When the candidate route is stored in the storage device 15, the cost calculation unit 83 calculates the cost of each candidate route (step ST5). When the cost of each candidate route stored in the storage device 15 is calculated, the guide route selection unit 44 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 ST6). The guide route selection unit 44 stores the selected candidate route in the storage device 15 as the guide route 48.

  By the way, when the road subordination coefficient is set as the cost calculation condition 46, the cost calculation unit 83 determines that “start point → L1 → N1 → L2 →→” when the search start point and end point are in the state of FIG. When calculating the cost of the candidate route "N2-> L3-> N3-> L4-> N4-> L5-> end point", the individual passage costs are calculated as follows. That is, the cost calculation unit 83 multiplies the cost information stored in the link data group for each link (for example, link L1) by the road subordination coefficient, and calculates the calculation result for each link (for example, link L1). Let it be a transit cost. The cost calculation unit 83 multiplies the cost information stored in the node data group for each node (for example, N1) by the road subordination coefficient, and sets the calculation result as an individual passage cost for that node (for example, N1). .

  Therefore, the cost of the candidate route “starting point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point” is the same as the cost information stored in the link data group 25 and the node data group 26. Compared to the case of each individual passing cost, it becomes larger. The guide route selection unit 44 then increases the cost of the candidate route “start point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point” and “start point → L6 → N4 → The cost of the candidate route “L5 → end point” is compared.

  As a result, for example, when the cost information stored in the link data group 25 and the node data group 26 is directly calculated as individual passing costs, the cost of the candidate route “start point → L6 → N4 → L5 → end point” is reduced. Even if the cost is higher than the cost of the candidate route “start point → L1 → N1 → L2 → N2 → L3 → N3 → L4 → N4 → L5 → end point”, the “start point → L1 → N1 → L2 → N2”. The cost of the candidate route “L3 → N3 → L4 → N4 → L5 → end point” can be increased, and the candidate route “start point → L6 → N4 → L5 → end point” can be easily selected as the guide route.

  As described above, in the car navigation system according to the third embodiment, the linear distance from the current location as the search starting point to the end point is a distance of 2 km or less, and the target local angle for viewing the end point from the start point is 90. If it is greater than or equal to 270 degrees and less than or equal to 270 degrees, it is determined that the end point of the search has been set to a close distance behind the current location, and the cost of each candidate route is calculated under conditions of road inferiority.

  Therefore, if the car navigation system determines that the end point of the search is set to be equal to or less than the predetermined distance behind the current location, the cost of the route that follows the road is relatively higher than the cost of the other route, The route that makes the vehicle make a U-turn is relatively lower than the cost of the route that travels along the way, and the route that makes the vehicle make a U-turn is likely to be generated as the guide route 48.

  As a result, in the case where the car navigation system can reach the destination 35 clearly earlier when the U-turn is made so as to meet the above-described conditions, It is possible to guide a route that makes a U-turn that can reach the destination 35 earlier than the guide route 48 in the case of searching.

  In the third embodiment, when the car navigation system determines that the end point of the search is set to be equal to or less than the predetermined distance behind the current location, the cost of the route that follows the road is changed to the cost of the other route. Compared to relatively high. In addition to this, for example, when it is determined that the end point of the search is set to be equal to or less than a predetermined distance behind the current location, the car navigation system determines the cost of the route along the road as in the third embodiment. The cost of the route for making the vehicle U-turn as in the second embodiment may be made relatively lower than the cost of the other route.

  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 embodiments, the cost calculation condition setting unit 41 determines whether or not the destination is set to be equal to or less than a predetermined distance behind the current location based on the straight line distance from the starting point to the end point of the search and the destination local angle. And a coefficient to be set as the cost calculation condition 46 is selected. In addition to this, for example, the cost calculation condition setting unit 41 determines whether or not the destination is set to be equal to or less than a predetermined distance behind the current location based on only the straight line distance from the starting point to the end point of the search, and calculates the cost. A coefficient set as the condition 46 may be selected. Further, the cost calculation condition setting unit 41 determines whether or not the destination is set to be equal to or less than a predetermined distance behind the current location based on the distance on the shortest route from the starting point to the ending point of the search instead of the linear distance. The coefficient set as the cost calculation condition 46 may be selected.

  In each of the above embodiments, the cost calculation condition setting unit 41 determines whether or not the linear distance from the search start point to the end point is 2 km or less, and selects a coefficient to be set as the cost calculation condition 46. In addition to this, for example, the cost calculation condition setting unit 41 determines whether the destination is a predetermined position behind the current location based on whether the distance is equal to or less than a predetermined arbitrary distance such as 1 km or less or 5 km or less. It may be determined whether or not the distance is set to be equal to or less than the distance, and a coefficient to be set as the cost calculation condition 46 may be selected. Similarly, the cost calculation condition setting unit 41 determines whether or not the destination is set to be equal to or less than a predetermined distance behind the current location based on whether or not the destination direction is within a range of 135 degrees to 225 degrees, for example. The coefficient to be determined and selected as the cost calculation condition 46 may be selected.

  In addition to this, for example, the cost calculation condition setting unit 41 determines whether or not there is a destination within a predetermined distance (for example, 1 km) from the road behind the host vehicle and the road behind the vehicle. Then, the coefficient set as the cost calculation condition 46 may be selected. The road behind the host vehicle may be further limited to a range within a predetermined distance from the current location. In these cases, the cost calculation condition setting unit 41 determines that the destination is set to be equal to or less than a predetermined distance behind the current location, for example, when the destination is within the above-described range, and the U-turn priority coefficient or the road is subordinate. A coefficient may be set.

  In each of the embodiments described above, the cost calculation condition setting unit 41 determines only whether or not the destination is set at a close distance behind the current location. In addition to this, for example, the cost calculation condition setting unit 41 determines the linear distance from the start point to the end point of the search or the destination direction in a plurality of stages, and sets different values of coefficients for each stage. It may be. Further, the cost calculation condition setting unit 41 may switch and set different types of coefficients such as a U-turn priority coefficient and a road subordination coefficient for each stage. Similarly, the value of the coefficient may be changed according to the size of the target local angle. For example, the coefficient value in the region near 180 degrees from the traveling direction of the host vehicle is lowered, and the coefficient value in the region near 90 degrees or 270 degrees is increased (<= 1).

  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 each of the above embodiments, the cost calculation units 43, 73, and 83 calculate one cost for each candidate route. In addition to this, for example, the cost calculation units 43, 73, and 83 may calculate a plurality of costs for each candidate route. In this case, the guide route selection unit 44 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.

  Each said embodiment is an example at the time of applying 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 pedestrians and bicycles. 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 storage contents of 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 at the time of route search realized 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 at the time of route guidance realized in the car navigation system by the CPU in FIG. 1 executing the route guidance program. FIG. 6 is a flowchart showing an operation during route search of the car navigation system shown in FIG. FIG. 7 is a display screen showing an example of a map and a guide route displayed on the liquid crystal device in FIG. FIG. 8 is a block diagram showing functions realized during route search in the car navigation system according to Embodiment 2 of the present invention. FIG. 9 is a flowchart showing an operation during route search of the car navigation system shown in FIG. FIG. 10 is a block diagram illustrating functions realized during route search in the car navigation system according to Embodiment 3 of the present invention. FIG. 11 is a flowchart showing an operation during route search of the car navigation system shown in FIG.

Explanation of symbols

15 Storage device (cost information storage means, priority coefficient storage means, subordinate coefficient storage means)
35 Destination 40 Current location mark (current location)
41 Cost calculation condition setting section (determination means)
43 Cost calculation part (cost calculation means)
44 Guide route selection unit (selection means)
56 Route Guide (Route Guide)
72 Cost calculation condition setting part (determination means)
73 Cost calculation part (cost calculation means)
82 Cost calculation condition setting part (determination means)
83 Cost calculation part (cost calculation means)

Claims (8)

When searching for a route, a guidance route search device that executes a road priority control that prioritizes a link and / or a node ahead in the traveling direction by lowering the cost information value of the link and / or node ahead in the traveling direction at the current location. In
Based on the current location as the starting point and the current traveling direction at the current location, determine whether the relative positional relationship of the destination or waypoint as the end point of the route search is below a predetermined distance behind the current location. A judgment means to
Cost information storage means for storing cost information of a link and / or a node selected as a route from the starting point to the ending point of the route search;
When it is determined by the determining means that the end point of the route search is set to be equal to or less than a predetermined distance behind the starting point of the route search, the road priority control is prohibited, and the link stored in the cost information storage unit and Cost calculation means for calculating the cost of the searched route using the cost information of the node and / or;
Selecting means for comparing costs of a plurality of searched routes using the cost calculated by the cost calculating means, and selecting one route as a guide route from the plurality of routes;
A guide route search device characterized by comprising: Whether the relative positional relationship of the destination or waypoint that is the end point of the route search is equal to or less than a predetermined distance behind the current location, based on the current location that is the starting point of the route search and the current traveling direction in the current location A judging means for judging whether or not
Cost information storage means for storing cost information of a link and / or a node selected as a route from the starting point to the ending point of the route search;
When the determination means determines that the end point of the route search is set to be equal to or less than a predetermined distance behind the start point of the route search, the cost information of each link and / or node stored in the cost information storage means is used. A cost calculation unit that adjusts the cost information so that a route that travels backward in the traveling direction is more easily selected than a route that travels forward in the traveling direction, and calculates the cost of the searched route;
Selecting means for comparing costs of a plurality of searched routes using the cost calculated by the cost calculating means, and selecting one route as a guide route from the plurality of routes;
A guide route search device characterized by comprising: The cost calculation means uses 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 is backward in the traveling direction from the current location. And calculate the cost of the searched route,
The selection means selects a route with the lowest cost as a guide route;
The guide route search device according to claim 2. Priority for storing a U-turn priority coefficient that decreases the value of cost information when obtaining cost information of a link or node that is backward in the traveling direction from the current location from the cost information of the link or node stored in the cost information storage means Coefficient storage means;
The cost calculation means, when it is determined by the determination means that the end point of the route search is set to be equal to or less than a predetermined distance behind the start point of the route search, for the link and / or node that is behind the current direction, Using the cost information obtained by applying the U-turn priority coefficient to the cost information of the link and / or node stored in the cost information storage means, calculating the cost of the searched route,
The selection means selects a route with the lowest cost as a guide route;
The guide route search device according to claim 2. The cost calculation means uses cost information having a value larger than the cost information of the link and / or node stored in the cost information storage means as cost information of the link and / or node that is forward in the traveling direction from the current location. And calculate the cost of the searched route,
The selection means selects a route with the lowest cost as a guide route;
The guide route search device according to claim 2 or 3, characterized in that. When obtaining cost information of a link or node that is forward in the traveling direction from the current location from the cost information of the link or node stored in the cost information storage means, a subordinate that stores a subordinate coefficient that increases the value of the cost information Coefficient storage means;
The cost calculation means, when the determination means determines that the end point of the route search is set to be equal to or less than a predetermined distance behind the start point of the route search, for the link or node that is forward in the traveling direction from the current location. Using the cost information obtained by applying the road or subordination coefficient to the cost information of the link or node stored in the information storage means, the cost of the searched route is calculated,
The selection means selects a route with the lowest cost as a guide route;
The guide route search device according to claim 5. Based on the current location as the starting point and the current traveling direction at that current location, determine whether the relative positional relationship of the destination or waypoint as the end point of the route search is below a predetermined distance behind the current location. And steps to
If it is determined that the end point of the route search is set to be equal to or less than the predetermined distance behind the starting point of the route search, the cost information value of the link and / or node ahead of the current direction in the current position is lowered and the forward direction Calculating the cost of the searched route using the cost information of the link and / or node stored in the cost information storage means,
Using the calculated cost, comparing the costs of a plurality of searched routes, and selecting one route as a guide route from among the plurality of routes;
A guide route search method characterized by comprising: Whether the relative positional relationship of the destination or waypoint that is the end point of the route search is equal to or less than a predetermined distance behind the current location, based on the current location that is the starting point of the route search and the current traveling direction in the current location A step of determining whether or not
When it is determined that the end point of the route search is set to be equal to or less than the predetermined distance behind the start point of the route search, the cost information of the link and / or node stored in the cost information storage means is used to move forward in the traveling direction. Adjusting the cost information so as to make it easier to select a route traveling backward in the traveling direction than the traveling route, and calculating a cost of the searched route;
Using the calculated cost, comparing the costs of a plurality of searched routes, and selecting one route as a guide route from among the plurality of routes;
A guide route search method characterized by comprising:

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