JP2014044156A - Route search system, route search device, route search method and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a route search system, a route search device, a route search method and a computer program, capable of reducing a processing time and a processing load on route search processing based on each of a plurality of search conditions.SOLUTION: A route search system creates an intersection list which is a list of intersections connecting candidates of a suitable route from a departure intersection to a destination intersection (S1); executes route search processing by a Dijkstra method, and when a center intersection is a destination intersection, determines whether or not a processing object intersection, which has not been set to a center intersection ever and of which an addition value of calculated search cost is smaller than that of the destination intersection, is present (S12); and when it is determined that the processing object intersection is present, continues and executes processing of cost calculation by setting the processing object intersection to a new center intersection (S13).

Description

  The present invention relates to a route search system, a route search device, a route search method, and a computer program for searching for a route from a departure place to a destination.

  2. Description of the Related Art In recent years, a navigation device is often mounted on a vehicle that provides vehicle travel guidance so that a driver can easily arrive at a desired destination. Here, the navigation device detects the current position of the vehicle by a GPS receiver or the like, acquires map data corresponding to the current position through a recording medium such as a DVD-ROM or HDD or a network, and displays it on a liquid crystal monitor. It is a device that can do. Further, the navigation device has a route search function for searching for an optimum route from the vehicle position to the destination when a desired destination is input, and sets the searched optimum route as a guide route, and displays it. A guide route is displayed on the screen, and when the user approaches an intersection, the user is surely guided to a desired destination by voice guidance. In recent years, some mobile phones, smartphones, PDAs (Personal Digital Assistants), personal computers, and the like have functions similar to those of the navigation device.

  In the route search function, the Dijkstra method is generally used as a route search method for searching for a route from a departure place to a destination. In addition, when searching for a route from the starting point to the destination, it is not possible to search for only one optimal route, but to search for a route that matches each search condition based on a plurality of search conditions. It has been broken. For example, Japanese Patent Laid-Open No. 2008-209208 discloses a search for a total of five routes that meet the five search conditions of a recommended route, a toll road priority route, a general road priority route, a distance priority route, and another route by the Dijkstra method. Is described.

JP 2008-209208 A (page 7-9, FIG. 1)

  Here, when a route is specified for each of a plurality of search conditions as in the technique described in Patent Document 1, the cost calculation condition is changed for each search condition, and the route search process by the Dijkstra method is performed as a search condition. It was executed repeatedly as many times. That is, when there are five search conditions as in Patent Document 1, a route search process based on a recommended route is first performed to identify a route that meets the recommended route search condition, and then based on a toll road priority route. Perform route search processing to identify routes that meet the search conditions for toll road priority routes, and repeat route search processing for general road priority routes, distance priority routes, and other routes in the same way, for a total of five routes Five routes were specified by performing a search process.

  However, if the configuration is such that the route search process is executed for each search condition as in the prior art, the processing time for the route search process becomes longer and the processing load increases as the search condition increases. In addition, since the route search processing that is repeatedly executed includes many overlapping processes, the work efficiency of the CPU is very poor.

  The present invention has been made to solve the above-described conventional problems, and when a route that matches the search condition is specified for each of a plurality of search conditions, a similar route search process is performed for each search condition. It is an object of the present invention to provide a route search system, a route search device, a route search method, and a computer program that can reduce processing time and processing load related to route search processing without having to be repeatedly executed.

  In order to achieve the object, the route search system (1) according to claim 1 of the present application specifies, as a route from the departure place to the destination, a suitable route that matches the search condition for each of the plurality of search conditions. An intersection list creation means for creating an intersection list that is a list of intersections that connect candidates for the suitable route from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination. 13), an initial center intersection setting means (13) for setting the departure point intersection as a center intersection, and for the adjacent intersection that is included in the intersection list and is adjacent to the center intersection, Cost calculation means (1) for calculating an added value of the search cost from the ground intersection to the adjacent intersection for each of the plurality of search conditions and for each of the adjacent intersections ) And the added value of the search cost for each of the plurality of search conditions calculated by the cost calculating means, and the adjacent intersection that minimizes the added value of the search cost regardless of the search condition is determined as a new central intersection. A result of repeatedly performing the processing of the cost calculation means and the central intersection update means for the central intersection newly set by the central intersection update means, An intersection coincidence judging means (13) for judging whether or not an intersection coincides with the destination intersection, and when the intersection coincidence judging means judges that the central intersection coincides with the destination intersection, the intersection Of the intersections included in the list, the search has not been set as the central intersection in the past and has been calculated by the cost calculation means. When it is determined that there is an intersection to be processed that determines whether there is an intersection to be processed whose intersection is smaller than the destination intersection, and the intersection determination means determines that there is an intersection to be processed The processing target intersection is set as a new center intersection, and the auxiliary processing means (13) for executing the processes of the cost calculation means and the center intersection update means, and the search cost calculated by the cost calculation means. Route specifying means (13) for specifying, for each search condition, a route having a minimum value of the search cost from the departure point intersection to the destination intersection as the matching route based on the addition value. It is characterized by that.

  Further, the route search system (1) according to claim 2 is the route search system according to claim 1, wherein the auxiliary processing means (13) determines the intersection to be processed by the intersection determination means (13). Until it is determined that there is no intersection, the processing of the cost calculation unit and the center intersection update unit using the processing target intersection as the center intersection is repeatedly performed.

  Moreover, the route search system (1) according to claim 3 is the route search system according to claim 1 or 2, wherein the intersection list creation means (13) converts the intersection list into the plurality of intersections. It is created by a plurality of lists divided for each search condition.

  Further, the route search system (1) according to claim 4 is the route search system according to claim 1 or 2, wherein the intersection list creation means (13) converts the intersection list into the intersection list. And a plurality of search conditions associated with each intersection included in the list.

  Further, the route search device (1) according to claim 5 is a route search system that specifies, as a route from a departure place to a destination, a suitable route that matches the search condition for each of a plurality of search conditions, An intersection list creating means (13) for creating an intersection list which is a list of intersections connecting candidates of the suitable route from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination; An initial center intersection setting means (13) for setting a ground intersection as a center intersection, and an adjacent intersection that is included in the intersection list and is adjacent to the center intersection from the departure point intersection to the adjacent intersection A cost calculation means (13) for calculating an added value of the search cost for each of the plurality of search conditions and for each adjacent intersection, and the cost calculation means Therefore, a central intersection updating unit that compares the calculated search cost addition values for each of the plurality of search conditions and sets the adjacent intersection that minimizes the search cost addition value regardless of the search conditions as a new central intersection. (13) and, as a result of repeatedly performing the processing of the cost calculation means and the central intersection update means for the central intersection newly set by the central intersection update means, the central intersection becomes the destination intersection. An intersection coincidence judging means (13) for judging whether or not they coincide with each other, and when the intersection coincidence judging means judges that the central intersection coincides with the destination intersection, the intersections included in the intersection list In addition, an added value of the search cost that has not been set at the central intersection in the past and is calculated by the cost calculation means is the purpose. An intersection determination unit (13) that determines whether or not there is a processing target intersection that is an intersection that is smaller than an intersection. When the intersection determination unit determines that there is the processing target intersection, the processing target intersection is newly determined. And the auxiliary processing means (13) for executing the processing of the cost calculating means and the central intersection updating means, and the starting cost based on the added value of the search cost calculated by the cost calculating means. Route specifying means (13) for specifying, for each search condition, a route having a minimum value of the search cost from a ground intersection to the destination intersection as the suitable route.

  The route search method according to claim 6 is a route search method for specifying a suitable route that meets the search condition for each of a plurality of search conditions as a route from the departure place to the destination. An intersection list creating step for creating an intersection list, which is a list of intersections that connect candidates for the suitable route from the departure point intersection corresponding to the destination point to the destination intersection corresponding to the destination, and the departure point intersection as a central intersection An initial center intersection setting step to be set; and for an intersection that is an intersection that is included in the intersection list and that is adjacent to the center intersection, an added value of the search cost from the departure point intersection to the adjacent intersection Calculated by a cost calculating step for calculating a plurality of search conditions and for each adjacent intersection, and the cost calculating step A central intersection update step of comparing the search cost addition values for each of the plurality of search conditions, and setting the adjacent intersection that minimizes the search cost addition value regardless of the search conditions as a new central intersection; It is determined whether or not the central intersection coincides with the destination intersection as a result of repeatedly performing the processing of the cost calculation step and the central intersection update step for the central intersection newly set by the intersection update step. When the intersection coincidence determining step and the intersection coincidence determining step determine that the central intersection coincides with the destination intersection, the intersections included in the intersection list are set as the central intersection in the past. And the added value of the search cost calculated by the cost calculation step is the destination intersection An intersection determination step for determining whether or not there is a processing target intersection that is a smaller intersection, and when the intersection determination step determines that there is the processing target intersection, the processing target intersection is set as a new central intersection. An auxiliary processing step that sets and executes the processing of the cost calculation step and the central intersection update step, and the destination intersection from the departure point intersection based on the added value of the search cost calculated by the cost calculation step And a route specifying step of specifying, for each search condition, a route that minimizes the added value of the search costs up to the search route.

  Furthermore, the computer program according to claim 7 is a computer program for causing a computer to specify a suitable route that matches a search condition for each of a plurality of search conditions as a route from the departure place to the destination. An intersection list creation function for creating an intersection list, which is a list of intersections that connect the candidates for the suitable route from the departure point intersection corresponding to the ground to the destination intersection corresponding to the destination, and the departure point intersection as a central intersection An initial center intersection setting function to be set, and for an adjacent intersection that is an intersection included in the intersection list and is adjacent to the center intersection, an addition value of a search cost from the departure point intersection to the adjacent intersection is calculated. A cost calculation function for calculating each of the plurality of search conditions and for each adjacent intersection, and the cost calculation Central intersection update that compares the search cost addition values for each of the plurality of search conditions calculated by the performance and sets the adjacent intersection that minimizes the search cost addition value as a new central intersection regardless of the search conditions As a result of repeating the function and the processing of the cost calculation function and the center intersection update function for the center intersection newly set by the center intersection update function, the center intersection matches the destination intersection. An intersection coincidence determining function for determining whether or not the center intersection has coincided with the destination intersection by the intersection coincidence determining function, of the intersections included in the intersection list in the past It is not set at the intersection and the added value of the search cost calculated by the cost calculation function is from the destination intersection. An intersection determination function that determines whether or not there is a processing target intersection that is a smaller intersection, and when the intersection determination function determines that there is the processing target intersection, the processing target intersection is set as a new central intersection. Based on the auxiliary processing function for executing the processing of the cost calculation function and the central intersection update function, and the added value of the search cost calculated by the cost calculation function, from the departure point intersection to the destination intersection A route specifying function for specifying, for each search condition, a route having a minimum added value of the search cost as the suitable route.

  According to the route search system according to claim 1, having the above-described configuration, when a route that matches the search condition is specified for each of a plurality of search conditions, the same route search process is repeated from the beginning for each search condition. There is no need to execute the processing, and the processing time and processing load related to the route search processing can be reduced.

  According to the route search system of claim 2, the processing of the cost calculation means and the central intersection update means using the processing target intersection as the central intersection is repeated until the intersection determination means determines that there is no processing target intersection. Therefore, even if the cost is calculated for a plurality of search conditions at the same time, it is possible to accurately calculate the minimum added value of the search cost from the departure point intersection to each intersection included in the intersection list. As a result, it is possible to appropriately specify the route having the minimum search cost addition value from the departure point intersection to the destination intersection as the matching route.

  Further, according to the route search system according to claim 3, since the intersection list is created from a plurality of lists divided into a plurality of search conditions, a route that matches the search conditions is specified for each of the plurality of search conditions. Even in such a case, it is possible to specify a suitable route for each search condition using a plurality of intersection lists with fewer processing steps than in the past.

  According to the route search system of claim 4, since the intersection list is created by one list in which a plurality of search conditions are associated with each intersection included in the intersection list, for each of the plurality of search conditions Even when each route that matches the search condition is specified, it is possible to specify a match route for each search condition using a single intersection list with fewer processing steps than in the past.

  In addition, according to the route search device of the fifth aspect, the same route search processing is repeatedly executed from the beginning for each search condition when specifying a route that matches the search condition for each of the plurality of search conditions. There is no need, and it becomes possible to reduce the processing time and processing load related to the route search processing.

  According to the route search method according to claim 6, when specifying a route that matches the search condition for each of a plurality of search conditions, the same route search process is repeatedly executed from the beginning for each search condition. There is no need, and it becomes possible to reduce the processing time and processing load related to the route search processing.

  Furthermore, according to the computer program of the seventh aspect, it is necessary to repeatedly execute the same route search process from the beginning for each search condition when specifying a route that matches the search condition for each of the plurality of search conditions. Therefore, it is possible to reduce processing time and processing load related to route search processing.

It is the block diagram which showed the structure of the navigation apparatus which concerns on this embodiment. It is a flowchart of the route search processing program concerning this embodiment. It is the figure which showed the candidate of the suitable path | route from the departure point intersection to the destination intersection. It is the figure which showed an example of the intersection list | wrist. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure explaining the specific example of the specific process of the suitable route based on an intersection list. It is the figure shown about the modification of an intersection list | wrist.

  Hereinafter, a route search system and a route search device according to the present invention will be described in detail with reference to the drawings based on an embodiment in which the navigation device is embodied. First, a schematic configuration of the navigation device 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a navigation device 1 according to this embodiment.

  As shown in FIG. 1, the navigation device 1 according to the present embodiment includes a current position detection unit 11 that detects a current position of a vehicle on which the navigation device 1 is mounted, a data recording unit 12 that records various data, Based on the input information, the navigation ECU 13 that performs various arithmetic processes, the operation unit 14 that receives operations from the user, and the route related to the route searched by the map around the vehicle and the route search process described later for the user A liquid crystal display 15 for displaying information and the like, a speaker 16 for outputting voice guidance regarding route guidance, a DVD drive 17 for reading a DVD as a storage medium, a probe center, a VICS (registered trademark: Vehicle Information and Communication System) center, and the like And a communication module 18 for communicating with the information center. That.

Below, each component which comprises the navigation apparatus 1 is demonstrated in order.
The current position detection unit 11 includes a GPS 21, a vehicle speed sensor 22, a steering sensor 23, a gyro sensor 24, and the like, and can detect the current vehicle position, direction, vehicle traveling speed, current time, and the like. . Here, in particular, the vehicle speed sensor 22 is a sensor for detecting a moving distance and a vehicle speed of the vehicle, generates a pulse according to the rotation of the driving wheel of the vehicle, and outputs a pulse signal to the navigation ECU 13. And navigation ECU13 calculates the rotational speed and moving distance of a driving wheel by counting the generated pulse. Note that the navigation device 1 does not have to include all the four types of sensors, and the navigation device 1 may include only one or more types of sensors.

  The data recording unit 12 is also a hard disk (not shown) as an external storage device and a recording medium, and a driver for reading the map information DB 31 and a predetermined program recorded on the hard disk and writing predetermined data on the hard disk And a recording head (not shown). The data recording unit 12 may be configured by a memory card, an optical disk such as a CD or a DVD, instead of the hard disk.

  Here, the map information DB 31 is, for example, link data 33 relating to roads (links), node data 34 relating to node points, search data 35 used for route search processing, facility data relating to facilities, and map display data for displaying a map. The storage means stores intersection data relating to each intersection, search data for searching for points, and the like.

  The link data 33 includes the width of the road to which the link belongs, the gradient, the cant, the bank, the road surface state, the number of lanes on the road, the number of lanes decreasing, The data representing the narrowing point, railroad crossing, etc., the corner, the radius of curvature, the intersection, the T-junction, the corner entrance and the exit, etc. The data representing the downhill road, the uphill road, etc. Regarding types, in addition to general roads such as national roads, prefectural roads and narrow streets, data representing toll roads such as national highways, urban highways, general toll roads, and toll bridges are recorded.

  The node data 34 includes actual road branch points (including intersections, T-junctions, etc.) and the coordinates (positions) of node points set for each road according to the radius of curvature, etc. Node attribute indicating whether a node is a node corresponding to an intersection, etc., a connection link number list that is a list of link numbers of links connected to the node, and an adjacency that is a list of node numbers of nodes adjacent to the node via the link Data relating to the node number list, the height (altitude) of each node point, and the like are recorded.

  Further, as the search data 35, various data used for route search processing for searching for a route from a departure place (for example, the current position of the vehicle) to a set destination as described later are recorded. Specifically, the cost of quantifying the appropriate degree as a route to an intersection (hereinafter referred to as an intersection cost), the cost of quantifying the appropriate degree as a route to a link constituting a road (hereinafter referred to as a link cost), etc. Cost calculation data used for calculating the search cost is stored.

Here, the intersection cost is set for each node corresponding to the intersection included in the route for which the search cost is to be calculated. The value is calculated according to the type of
The link cost is set for each link included in the route for which the search cost is to be calculated, and is calculated based on the link length, taking into account the road attributes, road type, road width, number of lanes, etc. Is done.

  Here, in the navigation device 1 according to the present embodiment, a route that matches the search condition (hereinafter referred to as a “matched route”) is specified for each search condition based on a plurality of search conditions, and specified by each search condition. One route desired by the user is finally set as a guide route from a plurality of compatible routes. As specific search conditions, priority should be given to shortening the required time to the destination and “recommendation” considering the ease of driving and the cost of driving, etc., and driving the toll road to the destination There are three types of search conditions: “priority toll road priority” and “general priority” that prioritizes traveling on a general road to the destination.

Further, the link cost calculation conditions are different for each search condition. For example, “Recommended” is based on link length, considering factors that affect travel time, such as the number of lanes, road type, and traffic congestion, and reducing the link cost so that links with shorter travel time have lower costs. calculate. In addition, consideration is given to the cost and ease of travel. In addition, in the “toll road priority”, in addition to the above-mentioned “recommended” calculation method, the link cost of links other than the link that is the road type of the toll road is increased (for example, doubled) to calculate the link cost . In “general priority”, in addition to the “recommended” calculation method, the link cost of the link, which is the road type of the toll road, is increased (for example, doubled) to calculate the link cost. That is, even for the same link, the link cost calculated for each search condition has a different value.
Then, the navigation ECU 13 performs a route search using the Dijkstra method based on the search cost such as the link cost and the intersection cost calculated for each search condition. Details of the route search processing by the Dijkstra method will be described later.

  On the other hand, the navigation ECU (Electronic Control Unit) 13 is an electronic control unit that controls the entire navigation device 1. The CPU 41 as an arithmetic device and a control device, and a working memory when the CPU 41 performs various arithmetic processes. ROM 43 in which a route search process program (see FIG. 2) and the like described below are recorded in addition to a RAM 42 for storing route data when a route is searched, an intersection list, and a control program. An internal storage device such as a flash memory 44 for storing a program read from the ROM 43 is provided. The navigation ECU 13 constitutes various means as processing algorithms. For example, the intersection list creating means creates an intersection list that is a list of intersections that connect candidates for suitable routes from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination. The initial center intersection setting means sets the departure point intersection as the center intersection. The cost calculation means calculates the added value of the search cost from the departure point intersection to the adjacent intersection for each of the plurality of search conditions for the adjacent intersection that is included in the intersection list and is adjacent to the central intersection. Calculate for each intersection. The center intersection update unit compares the added values of the search costs for each of the plurality of search conditions, and sets an adjacent intersection that minimizes the added value of the search costs as a new center intersection regardless of the search conditions. The intersection coincidence determining means, as a result of repeatedly performing the processing of the cost calculating means and the central intersection updating means for the central intersection newly set by the central intersection updating means, has the central intersection matched the destination intersection? Determine whether or not. When it is determined that the center intersection coincides with the destination intersection, the intersection determination means is not set as the center intersection in the past among the intersections included in the intersection list, and is calculated by the cost calculation means. It is determined whether or not there is an intersection to be processed that is an intersection whose search cost addition value is smaller than the destination intersection. The auxiliary processing means sets the processing target intersection as a new central intersection when the intersection determination means determines that there is a processing target intersection, and executes the processing of the cost calculation means and the central intersection update means. The route specifying means specifies, for each search condition, a route having the minimum search cost addition value from the departure point intersection to the destination intersection for each search condition based on the addition value of the search cost calculated by the cost calculation means. .

  The operation unit 14 is operated when inputting a starting point as a travel start point and a destination as a travel end point, and includes a plurality of operation switches (not shown) such as various keys and buttons. Then, the navigation ECU 13 performs control to execute various corresponding operations based on switch signals output by pressing the switches. The operation unit 14 can also be configured by a touch panel provided on the front surface of the liquid crystal display 15. Moreover, it can also be comprised with a microphone and a speech recognition apparatus.

The liquid crystal display 15 includes a map image including a road, traffic information, operation guidance, operation menu, key guidance, guidance route from the departure point to the destination, guidance information along the guidance route, news, weather forecast, Time, mail, TV program, etc. are displayed.
Moreover, when navigation ECU13 performs the route search process mentioned later, it displays about the suitable route specified for every some search condition based on the search result. In addition, when the compatible route travels on a toll road such as an expressway, the fee required for traveling is also displayed. Then, the user selects a route to be a guide route from among the plurality of displayed compatible routes.

  The speaker 16 outputs voice guidance for guiding traveling along the guidance route based on an instruction from the navigation ECU 13 and traffic information guidance.

  The DVD drive 17 is a drive that can read data recorded on a recording medium such as a DVD or a CD. Based on the read data, music and video are reproduced, the map information DB 31 is updated, and the like.

  The communication module 18 is a communication device for receiving traffic information composed of information such as traffic jam information, regulation information, and traffic accident information transmitted from a traffic information center, for example, a VICS center or a probe center. For example, a mobile phone or DCM is applicable.

  Next, a route search processing program executed by the CPU 41 in the navigation device 1 according to this embodiment having the above-described configuration will be described with reference to FIG. FIG. 2 is a flowchart of the route search processing program according to this embodiment. Here, the route search processing program is executed when a predetermined operation (for example, a destination setting operation) for performing a route search is received in the navigation device 1, and from the departure point to the destination for each of a plurality of search conditions. This is a program for searching for a suitable path using the Dijkstra method. In the following description of the embodiment, only the link cost is considered as the search cost for the sake of simplification, and the intersection cost and other costs are not considered. Note that the program shown in the flowchart of FIG. 2 below is stored in the RAM 42 and the ROM 43 provided in the navigation device 1 and is executed by the CPU 41.

  First, in step (hereinafter abbreviated as S) 1 in the route search processing program, the CPU 41 creates and creates an intersection list based on the departure point intersection, the destination intersection, and the map information stored in the map information DB 31. The intersection list thus recorded is stored in a storage medium such as the RAM 42. Further, initialization of the created intersection list is also performed. The departure point intersection is an intersection corresponding to the departure point (for example, the current position of the vehicle) (for example, the intersection closest to the departure point), and the destination intersection is the intersection corresponding to the set destination (for example, the destination) (The intersection closest to the ground).

  Here, the intersection list is a list of intersections (including a departure point intersection and a destination intersection) that connect candidates for suitable routes from the departure point intersection to the destination intersection. The intersection list includes, for each listed intersection, a cost value T indicating a minimum added value of the search cost from the departure point intersection to the intersection, and an intersection that passes immediately before the cost value T is realized. A certain previous intersection is associated with a candidate flag indicating a setting candidate for the central intersection.

  In the following description, the case where the route search process from the departure point intersection A to the destination intersection I shown in FIG. 3 is performed will be described as a specific example. When the route search process from the departure point intersection A to the destination intersection point I shown in FIG. 3 is performed, the nine intersection points A connecting the links that can form the suitable route from the departure point intersection point A to the destination intersection point I. An intersection list in which ˜I is listed is created (see FIG. 4). Further, the intersection list is created by a plurality of lists divided for each search condition. In other words, in this embodiment, priority is given to shortening the required time to the destination, and “recommendation” that takes into account the ease of travel and the cost associated with travel, and priority to travel on the toll road to the destination. Since the route search is performed under three types of search conditions, “priority road priority” and “general priority” that prioritizes traveling on the general road to the destination, a total of three intersection lists are created.

  In the initialization process of the intersection list executed in S1, the cost value T associated with all the intersections listed as shown in FIG. 4 is set to infinity, the immediately preceding intersection is not associated, The candidate flag is set to “OFF (0)”.

  Next, in S2, the CPU 41 performs an initialization process for the departure point intersection. Specifically, as shown in FIG. 5, the cost value T associated with the departure point intersection A in the intersection list is set to 0, and the candidate flag is set to “ON (1)”.

  Subsequently, in S3, the CPU 41 sets a central intersection. Specifically, among the intersections for which the candidate flag is set to “ON (1)”, the intersection associated with the minimum cost value T regardless of the search condition is set as the central intersection. When the process of S3 is executed for the first time after the start of the route search processing program, the candidate flag is set to “ON (1)” only at the departure point intersection, so that the departure point intersection is always the center intersection. Will be set. On the other hand, when the process of S3 is performed after the next time, if the adjacent intersection adjacent to the intersection set as the central intersection (if the associated candidate flag is “ON (1)”, past adjacent intersections will also be displayed. An intersection associated with the minimum cost value T is set as the central intersection. Further, as described above, in S3, the intersection with the minimum cost value T is selected as the central intersection regardless of the search condition. That is, even if the intersection is associated with a cost value T (for example, 15) larger than that of other intersections in the “recommended” intersection list, the cost value T (( For example, if 8) is associated, it may be set at the center intersection.

  Thereafter, in S4, the CPU 41 determines whether or not the intersection newly set as the central intersection in S3 is the destination intersection.

  When it is determined that the intersection newly set as the central intersection in S3 is the destination intersection (S4: YES), the process proceeds to S12. On the other hand, when it is determined that the intersection newly set as the central intersection in S3 is not the destination intersection (S4: NO), the process proceeds to S5.

  Thereafter, in S5, the CPU 41 sets the candidate flag associated with the intersection newly set as the central intersection in S3 to “OFF (0)”. For example, when the departure point intersection A is set as the central intersection in S3, the candidate flag associated with the departure point intersection A is set to “OFF (0)” as shown in FIG.

  The subsequent processing of S6 to S11 is repeatedly performed for each intersection (hereinafter referred to as an adjacent intersection) adjacent to the intersection set as the central intersection in S3 among the intersections listed in the intersection list and for each search condition. Is done.

  First, in S6, the CPU 41 reads the cost value T currently associated with the adjacent intersection in the intersection list.

  Next, in S <b> 7, the CPU 41 calculates an addition value C of the search cost for a route from the departure point intersection to the adjacent intersection via the central intersection. Specifically, a value obtained by adding the search cost from the central intersection to the adjacent intersection to the cost value T associated with the central intersection is the added value C.

  Thereafter, in S8, the CPU 41 determines that the added value C of the search cost for the route from the departure point intersection to the adjacent intersection through the central intersection calculated in S7 is the cost value currently associated with the adjacent intersection. It is determined whether or not it is smaller than T.

  If the added value C of the search cost of the route from the departure point intersection to the adjacent intersection through the central intersection calculated in S7 is smaller than the cost value T currently associated with the adjacent intersection. If it is determined (S8: YES), it is estimated that the optimum route to the adjacent intersection is a route via the current center intersection. Thereafter, the process proceeds to S9. On the other hand, the addition value C of the search cost for the route from the departure point intersection to the adjacent intersection via the central intersection calculated in S7 is the same as the cost value T currently associated with the adjacent intersection. Or when it determines with it being larger than the cost value T (S8: NO), it estimates that the optimal path | route to this adjacent intersection is not the path | route which passed through the present center intersection. And it transfers to the process with respect to another search condition or another adjacent intersection, without updating cost value T etc. which were matched with this adjacent intersection.

  In S9, the CPU 41 updates the cost value T currently associated with the adjacent intersection to the addition value C calculated in S7.

  In S10, the CPU 41 updates the immediately preceding intersection associated with the adjacent intersection to the current center intersection.

  Further, in S11, the CPU 41 sets the candidate flag associated with the adjacent intersection to “ON (1)”. That is, the adjacent intersection becomes a new center intersection candidate.

  And after the process of S6-S11 is performed with respect to all the adjacent intersections adjacent to the center intersection among the intersections listed in the intersection list and all the search conditions, the process returns to S3.

  For example, when the departure point intersection A is set as the central intersection in S3, the processes of S6 to S11 are performed on the intersections B and C adjacent to the departure point intersection A as shown in FIG. The Then, for each search condition, a new cost value T is associated based on the link cost shown in FIG. 2, the intersection A is associated with the immediately preceding intersection, and the candidate flag is set to “ON (1)”. . Thereafter, when the process of S3 is performed, the cost value T associated with the intersection B of the “general priority” intersection list is “8”, which is the smallest, so the intersection B is set as a new central intersection, and so on. Will be executed. First, as shown in FIG. 8, the candidate flag for the intersection B newly set as the central intersection is set to “OFF (0)” (S5). Thereafter, as shown in FIG. 9, the processes of S6 to S11 are performed on the intersection C, the intersection D, and the intersection E adjacent to the intersection B newly set as the central intersection. Similarly, the process is repeated until the center intersection becomes the destination intersection.

  Then, in S12 executed when it is determined that the intersection newly set as the central intersection in S3 in the determination process of S4 is the destination intersection, the CPU 41, among the intersections included in the intersection list, The candidate flag is “ON (1)” (that is, an intersection that has become a candidate for the central intersection but has not been set as the central intersection), and the cost value T is smaller than the destination intersection under at least one search condition. It is determined whether there is an associated intersection (hereinafter referred to as a process target intersection).

  If it is determined that there is an intersection to be processed among the intersections included in the intersection list (S12: YES), the process proceeds to S13. On the other hand, when it is determined that there is no processing target intersection among the intersections included in the intersection list (S12: NO), the process proceeds to S14.

  In S13, the CPU 41 sets the processing target intersection as the central intersection. Thereafter, the processing after S5 is executed based on the central intersection newly set in S13. Thereafter, the processes in and after S13 are repeatedly executed until it is determined in S12 that there is no intersection to be processed. Note that the processing after S13 is executed only for the intersection list of the search conditions (for example, “recommended” and “toll road priority” in the example shown in FIG. 10) determined to be the target intersection. May be.

For example, FIG. 10 is a diagram illustrating an intersection list after the processes of S4 to S11 are performed in a state where the central intersection is set to the intersection G. In the intersection list shown in FIG. 10, among intersections whose candidate flag is set to “ON (1)”, the intersection associated with the minimum cost value T is the destination intersection I regardless of the search condition. In step S3, the destination intersection I is set as the center intersection. However, in the “recommended” and “toll road priority” intersection lists, an intersection (processing target intersection) H with a candidate flag “ON (1)” and associated with a cost value T smaller than the destination intersection. Next, the intersection H is set as a new central intersection (S13), and the processes after S5 are executed. As a result, the processing of S6 to S11 is executed for the intersection G and the intersection I adjacent to the intersection H as shown in FIG.
Thereafter, as a result of executing the processes after S13, the destination intersection I is set as the central intersection again in S3, and the process proceeds to the determination process of S12. In the intersection list shown in FIG. 11, the candidate flag is “ON (1)” and the processing target intersection associated with the cost value T smaller than the destination intersection does not exist in any search condition. It is determined NO in the determination process of S12, and the process proceeds to S14.

  In S14, the CPU 41 sets the candidate flag associated with the central intersection (destination intersection) to “OFF (0)” as shown in FIG.

  Thereafter, in S15, the CPU 41 specifies a route connecting the previous intersection from the destination intersection to the departure point intersection as a suitable route for each search condition based on the final intersection list. As a result, a route that minimizes the added value of the search cost from the departure point intersection to the destination intersection is specified for each search condition as a suitable route. For example, when the intersection list shown in FIG. 12 is finally obtained, a route connecting intersection A → intersection B → intersection E → intersection G → intersection I is specified as a suitable route for the “recommended” search condition. Is done. In addition, a route connecting intersection A → intersection C → intersection F → intersection H → intersection I is specified as a suitable route for the search condition of “toll road priority”. Further, a route connecting intersection A → intersection B → intersection C → intersection E → intersection D → intersection G → intersection I is specified as a suitable path for the search condition of “general priority”.

  Note that the suitable route for each search condition specified in S15 is guided to the user via the liquid crystal display 15 or the like. Then, one suitable route selected based on the subsequent user operation is set as the guide route of the navigation device 1, and travel guidance based on the set guide route is performed.

As described above in detail, in the navigation device 1, the route search method by the navigation device 1, and the computer program executed by the navigation device 1 according to the present embodiment, candidates for suitable routes from the departure point intersection to the destination intersection are connected. An intersection list that is a list of intersections to be created is created (S1), the departure intersection is set as the first central intersection (S3), and is an intersection that is included in the intersection list and is adjacent to the central intersection. For each of the plurality of search conditions and for each of the adjacent intersections (S6 to S9), and the calculated search cost for each of the plurality of search conditions And set the adjacent intersection that minimizes the added value of the search cost regardless of the search condition as a new central intersection ( 3) When the newly set center intersection becomes the destination intersection, among the intersections included in the intersection list, the center intersection has not been set in the past, and the calculated search cost addition value Is determined whether there is a processing target intersection that is smaller than the destination intersection (S12), and if it is determined that there is a processing target intersection, the processing target intersection is set as a new central intersection. The cost calculation process is continuously executed (S13), and a route that minimizes the added value of the search cost from the departure point intersection to the destination intersection is specified for each search condition (S15). When each route that matches the search condition is specified for each search condition, it is not necessary to repeat the same route search process from the beginning for each search condition, and the processing time and processing related to the route search process It becomes possible to reduce the collateral.
In addition, since the cost calculation process using the processing target intersection as the central intersection is repeatedly executed until the intersection determination unit determines that there is no processing target intersection, the cost calculation for a plurality of search conditions may be performed simultaneously. Thus, it is possible to accurately calculate the minimum added value of the search cost from the departure point intersection to each intersection included in the intersection list. As a result, it is possible to appropriately specify the route having the minimum search cost addition value from the departure point intersection to the destination intersection as the matching route.
In addition, since the intersection list is created from a plurality of lists divided into a plurality of search conditions, a plurality of intersection lists are used even when specifying a route that matches the search conditions for each of the plurality of search conditions. Thus, it is possible to specify the suitable route for each search condition with fewer processing steps than in the past.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, the configuration is such that a suitable route is specified for each of three types of search conditions. In this case, it is necessary to create an intersection list corresponding to the number of search conditions.

  In the present embodiment, the intersection list is created by a plurality of lists divided for each of a plurality of search conditions, but the intersection list is associated with a plurality of search conditions for each intersection included in the intersection list. You may create by the list of. For example, FIG. 13 shows an example in which the intersection list shown in FIG. 12 is created as one list. Even in the case where the intersection list shown in FIG. 13 is used, it is possible to specify a suitable route for each search condition with fewer processing steps than in the prior art, as in the present embodiment.

  In the present embodiment, the search cost addition value C is calculated in consideration of only the link cost necessary for traveling on the link. However, the intersection cost and other costs necessary for passing through the intersection are calculated. It is good also as a structure which calculates the addition value C of search cost in consideration of.

  In addition to the navigation device, the present invention can be applied to a device having a route search function. For example, the present invention can be applied to a mobile terminal such as a mobile phone or a smartphone, a personal computer (hereinafter referred to as a mobile terminal). Further, the present invention can be applied to a system including a server and a mobile terminal. In that case, each step of the route search processing program (FIG. 2) described above may be configured to be implemented by either a server or a mobile terminal. In addition, when the present invention is applied to a mobile terminal or the like, the present invention can also be applied to a search for a route for a moving body other than a vehicle, for example, a user such as a mobile terminal or a two-wheeled vehicle.

1 Navigation device 13 Navigation ECU
41 CPU
42 RAM
43 ROM

Claims (7)

A route search system for identifying a suitable route that matches a search condition for each of a plurality of search conditions as a route from a starting point to a destination,
An intersection list creating means for creating an intersection list, which is a list of intersections connecting candidates of the suitable route from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination;
Initial center intersection setting means for setting the departure point intersection as a center intersection;
For an adjacent intersection that is an intersection that is included in the intersection list and that is adjacent to the central intersection, an addition value of a search cost from the departure point intersection to the adjacent intersection is set for each of the plurality of search conditions and the adjacent intersection. A cost calculation means for calculating each time;
The added value of the search cost for each of the plurality of search conditions calculated by the cost calculating unit is compared, and the adjacent intersection that minimizes the added value of the search cost regardless of the search condition is set as a new central intersection. Center intersection update means,
Whether or not the central intersection coincides with the destination intersection as a result of repeating the process of the cost calculation means and the central intersection update means for the central intersection newly set by the central intersection update means Intersection coincidence judging means for judging
When the intersection coincidence determining unit determines that the central intersection coincides with the destination intersection, the intersections included in the intersection list have not been set as the central intersection in the past, and the cost An intersection determination unit that determines whether or not there is a processing target intersection that is an intersection where the addition value of the search cost calculated by the calculation unit is smaller than the destination intersection;
An auxiliary processing unit that sets the processing target intersection as a new central intersection when the intersection determination unit determines that there is the processing target intersection, and executes the processes of the cost calculation unit and the central intersection update unit; ,
Based on the addition value of the search cost calculated by the cost calculation means, a route that minimizes the addition value of the search cost from the departure point intersection to the destination intersection is defined as the matching route for each of the search conditions. A route search system comprising: a route specifying means for specifying.   The auxiliary processing means repeatedly executes the processing of the cost calculation means and the central intersection update means with the processing target intersection as the central intersection until the intersection determination means determines that there is no processing target intersection. The route search system according to claim 1.   3. The route search system according to claim 1, wherein the intersection list creation unit creates the intersection list from a plurality of lists divided for each of the plurality of search conditions.   3. The intersection list creating means creates the intersection list from one list in which the plurality of search conditions are associated with each intersection included in the intersection list. The route search system described in 1. A route search device for specifying a suitable route that matches the search condition for each of a plurality of search conditions as a route from the starting point to the destination,
An intersection list creating means for creating an intersection list, which is a list of intersections connecting candidates of the suitable route from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination;
Initial center intersection setting means for setting the departure point intersection as a center intersection;
For an adjacent intersection that is an intersection that is included in the intersection list and that is adjacent to the central intersection, an addition value of a search cost from the departure point intersection to the adjacent intersection is set for each of the plurality of search conditions and the adjacent intersection. A cost calculation means for calculating each time;
The added value of the search cost for each of the plurality of search conditions calculated by the cost calculating unit is compared, and the adjacent intersection that minimizes the added value of the search cost regardless of the search condition is set as a new central intersection. Center intersection update means,
Whether or not the central intersection coincides with the destination intersection as a result of repeating the process of the cost calculation means and the central intersection update means for the central intersection newly set by the central intersection update means Intersection coincidence judging means for judging
If it is determined by the intersection coincidence determining means that the central intersection coincides with the destination intersection, the intersections included in the intersection list have not been set as the central intersection in the past, and at least one An intersection determination unit that determines whether or not there is a processing target intersection that is an intersection in which an addition value of the search cost calculated by the cost calculation unit under the search condition is smaller than the destination intersection;
An auxiliary processing unit that sets the processing target intersection as a new central intersection when the intersection determination unit determines that there is the processing target intersection, and executes the processes of the cost calculation unit and the central intersection update unit; ,
Based on the addition value of the search cost calculated by the cost calculation means, a route that minimizes the addition value of the search cost from the departure point intersection to the destination intersection is defined as the matching route for each of the search conditions. A route search apparatus comprising: a route specifying means for specifying. A route search method for identifying a suitable route that matches a search condition for each of a plurality of search conditions as a route from a starting point to a destination,
An intersection list creating step of creating an intersection list that is a list of intersections connecting candidates of the suitable route from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination; and
An initial center intersection setting step for setting the departure point intersection as a center intersection;
For an adjacent intersection that is an intersection that is included in the intersection list and that is adjacent to the central intersection, an addition value of a search cost from the departure point intersection to the adjacent intersection is set for each of the plurality of search conditions and the adjacent intersection. A cost calculation step for each calculation,
The added value of the search cost for each of the plurality of search conditions calculated by the cost calculating step is compared, and the adjacent intersection that minimizes the added value of the search cost regardless of the search condition is set as a new central intersection. A central intersection update step;
Whether or not the center intersection coincides with the destination intersection as a result of repeatedly performing the cost calculation step and the center intersection update step for the center intersection newly set by the center intersection update step An intersection coincidence judging step for judging
If it is determined in the intersection match determination step that the center intersection matches the destination intersection, the intersections included in the intersection list have not been set as the center intersection in the past, and the cost An intersection determination step for determining whether or not there is a processing target intersection that is an intersection in which the addition value of the search cost calculated by the calculation step is smaller than the destination intersection;
An auxiliary processing step for setting the processing target intersection as a new central intersection when the intersection determination step determines that there is the processing target intersection, and executing the processing of the cost calculation step and the central intersection update step; ,
Based on the added value of the search cost calculated by the cost calculating step, a route with the minimum added value of the search cost from the departure point intersection to the destination intersection is defined as the matching route for each of the search conditions. A route searching method comprising: a route specifying step for specifying. On the computer,
A computer program for specifying a suitable route that matches the search condition for each of a plurality of search conditions as a route from the starting point to the destination,
An intersection list creation function for creating an intersection list, which is a list of intersections connecting candidates of the suitable route from the departure point intersection corresponding to the departure point to the destination intersection corresponding to the destination; and
An initial center intersection setting function for setting the departure point intersection as a center intersection;
For an adjacent intersection that is an intersection that is included in the intersection list and that is adjacent to the central intersection, an addition value of a search cost from the departure point intersection to the adjacent intersection is set for each of the plurality of search conditions and the adjacent intersection. A cost calculation function to calculate for each,
The added value of the search cost for each of the plurality of search conditions calculated by the cost calculation function is compared, and the adjacent intersection that minimizes the added value of the search cost regardless of the search condition is set as a new central intersection. Central intersection update function,
Whether the center intersection coincides with the destination intersection as a result of repeatedly performing the processing of the cost calculation function and the center intersection update function for the center intersection newly set by the center intersection update function An intersection coincidence judging function for judging
When it is determined by the intersection match determination function that the center intersection matches the destination intersection, the intersections included in the intersection list have not been set as the center intersection in the past, and the cost An intersection determination function for determining whether or not there is a processing target intersection that is an intersection where the added value of the search cost calculated by the calculation function is smaller than the destination intersection;
An auxiliary processing function that sets the processing target intersection as a new central intersection when the intersection determination function determines that the processing target intersection is present, and executes processing of the cost calculation function and the central intersection update function; ,
Based on the added value of the search cost calculated by the cost calculating function, a route that minimizes the added value of the search cost from the departure point intersection to the destination intersection is defined as the matching route for each of the search conditions. A path identification function to identify,
A computer program for executing

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