JP6487739B2 - Route search system, route search method and computer program - Google Patents

Description

  The present invention relates to a route search system, a route search method, and a computer program for searching for a route.

  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, tablet terminals, 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. Here, in the Dijkstra method, a search cost (link cost, intersection cost) is calculated for each node corresponding to each link or intersection included in the route, and an optimum value is calculated based on the added value of the calculated search costs. Identify the route. Further, conventionally, a route is searched in consideration of user's preference. For example, Japanese Patent Laid-Open No. 2009-42051 specifies the frequency of use of links classified by generation, vehicle type, etc. by statistically collecting collected probe information, and costs such that links with high usage frequency are easily selected as routes. A technique for adjusting the frequency is proposed.

Japanese Patent Laying-Open No. 2009-42051 (page 6-8, FIG. 2)

  However, in the above-mentioned Patent Document 1, the cost is adjusted in units of links based on the link usage frequency statistics in units of links, and the route is not considered. Specifically, when the usage frequency is specified from the past driving history, the frequency of use of each link is not considered, regardless of which departure history from which the collected past driving history has traveled. Is determined. Also, when searching for a route, the cost is adjusted so that it is easy to select a link for a link that has been identified as being frequently used by the user, without considering where the departure point or destination is located. Yes. However, in practice, the link usage frequency varies depending on where the user's departure point or destination is located, and the technique of Patent Document 1 cannot search for an optimum route according to the user's preference. was there.

  For example, a case where the area X and the area Y are connected by two links A and B as shown in FIG. 14 will be described. In such a case, when going from area X to area Y, link A is easier to travel than link B and is more frequently used. On the other hand, when going from area Y to area X, link B is link A. It is also conceivable that the vehicle is easy to travel and frequently used. However, even in the situation shown in FIG. 14 in Patent Document 1, the link A travels even when searching for a route from the area Y to the area X if the total usage frequency is higher than that of the link B. Cost adjustment is performed so that the link A that is less likely to travel than the easy link B is easily selected.

  The present invention has been made in order to solve the above-described conventional problems, and reflects the user's preference in units of routes, not in units of links. Another object of the present invention is to provide a route search system, a route search method, and a computer program that make it possible to search for an appropriate route.

In order to achieve the object, a route search system according to the present invention includes a point setting unit for setting a departure point and a destination of a vehicle, and the destination from the departure point where the vehicle has been set by the point setting unit in the past. Route information acquisition means for acquiring route information for specifying a route that has traveled up to and from the departure point to the destination based on the route information acquired by the route information acquisition means. that path, have a, a search criterion setting means for setting a calculation reference of the cost value in the route search processing to approach most route specified by the route information calculation reference of the cost values, road attribute A cost factor defined for each route, and the route search process from the departure place to the destination is performed by the route search process from the departure place to the destination. Calculating a cost value of a search target link that is an elephant link using a cost coefficient corresponding to a road attribute of the search target link, specifying a route based on the calculated cost value, and the search reference setting means Defines the cost coefficient as a parameter for each road attribute, changes the parameter, and the parameter for each road attribute by comparing and evaluating the route searched based on the changed parameter and the route specified by the route information And an optimum value of the parameter for each identified road attribute is set as a calculation reference for the cost value .

The route search method according to the present invention is a route search method for searching for a recommended route using the cost values of links or nodes constituting the route. Specifically, the point setting unit sets the starting point and destination of the vehicle, and the route information acquisition unit includes the route from the starting point where the vehicle has been set by the point setting unit in the past to the destination. A step of acquiring route information for identifying a route that has traveled, and a search reference setting unit, based on the route information acquired by the route information acquisition unit, by a route search process from the departure place to the destination path to be searched is, have a, and setting a calculation reference of the cost value in the route search processing to approach most route specified by the route information calculation reference of the cost value for each road attribute The route search process from the departure place to the destination is performed as a search target by the route search process from the departure place to the destination. A cost value of a search target link that is a link to be calculated using a cost coefficient corresponding to a road attribute of the search target link, a route is specified based on the calculated cost value, and the search reference setting unit is The cost coefficient is defined as a parameter for each road attribute, and the parameter is optimized for each road attribute by comparing and evaluating the route searched based on the changed parameter and the route specified by the route information. A value is specified, and an optimum value of the parameter for each specified road attribute is set as a calculation reference for the cost value .

The computer program according to the present invention is a computer program for searching for a recommended route using the cost values of links or nodes constituting the route. Specifically, the computer identifies a point setting means for setting the starting point and destination of the vehicle, and a route on which the vehicle has traveled from the starting point to the destination set by the point setting means in the past. A route information acquisition unit that acquires route information to be searched, and a route that is searched by a route search process from the departure point to the destination based on the route information acquired by the route information acquisition unit. A computer program for functioning as search criterion setting means for setting a calculation criterion for a cost value in the route search processing so as to be closest to the route specified by the road search processing, wherein the calculation criterion for the cost value is a road A cost factor defined for each attribute, and a route search process from the departure place to the destination is a route search from the departure place to the destination. Calculating a cost value of a search target link that is a link to be searched by using a cost coefficient corresponding to a road attribute of the search target link, specifying a route based on the calculated cost value, and The reference setting means defines a cost coefficient as a parameter for each road attribute, changes the parameter, and compares the path searched based on the changed parameter with the path specified by the path information for each road attribute. The optimal value of the parameter is specified, and the optimal value of the parameter for each specified road attribute is set as a calculation reference for the cost value .

  According to the route search system, the route search method, and the computer program according to the present invention having the above-described configuration, a route close to the route in which the host vehicle actually traveled from the same starting point to the destination in the past is searched. Since the calculation standard of the cost value is set, it is possible to reflect the user's preference not in units of links but in units of routes. Therefore, it is possible to search for an appropriate route in accordance with the user's preference in consideration of the departure point and the destination.

1 is a schematic configuration diagram illustrating a route search system according to the present embodiment. It is the block diagram which showed the structure of the route search system which concerns on this embodiment. It is the figure which showed an example of the probe information memorize | stored in probe information DB. It is the block diagram which showed the structure of the navigation apparatus which concerns on this embodiment. It is a flowchart of the probe information maintenance program which concerns on this embodiment. It is the figure which showed the example of the evaluation point set with respect to a driving | running track, and an evaluation point. It is a flowchart of the reference | standard calculation processing program which concerns on this embodiment. It is the figure which showed an example of the parameter prescribed | regulated for every road attribute. It is the figure which showed an example of the initial value of the parameter prescribed | regulated for every road attribute. It is the figure which showed the example of a change of the parameter prescribed | regulated for every road attribute. It is a figure explaining the calculation method of a score. It is the figure which showed the example of the parameter of the optimal value finally specified. It is a flowchart of the route search processing program concerning this embodiment. It is a figure explaining the problem of the prior art.

  DETAILED DESCRIPTION Hereinafter, a route search system according to the present invention will be described in detail with reference to the drawings based on an embodiment that is embodied. First, a schematic configuration of the route search system 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram showing a route search system 1 according to the present embodiment. FIG. 2 is a block diagram showing the configuration of the route search system 1 according to the present embodiment.

  As shown in FIG. 1, the route search system 1 according to the present embodiment collects probe information from each vehicle 3 equipped with a navigation device 2 and each vehicle 3, and creates various information based on the collected probe information. It is basically composed of a probe center 4 that performs distribution. In addition, it is good also as a structure which uses communication terminals, such as a smart phone and a tablet-type terminal, instead of the navigation apparatus 2. FIG.

  The vehicle 3 is a vehicle that travels on roads throughout the country, and forms a probe car system as a probe car together with a probe center 4 described later. Here, the probe car system is a system that collects information using a vehicle as a sensor. Specifically, the vehicle 3 includes the speed data and the operation status of each system such as the steering operation and the shift position together with the GPS position information. Hereinafter, it is a system that is periodically transmitted to the probe center 4 via a communication module) and the collected data is reused as various information on the center side.

  In addition, the probe center 4 collects and accumulates probe information including the current time and travel information transmitted from each vehicle 3 traveling all over the country, and the route search processing is performed in the navigation device 2 from the accumulated probe information. This is an information distribution center that generates distribution information (probe statistical information) such as a calculation standard for cost values when performing the operation, and distributes the generated distribution information to the vehicle 3.

  A navigation device 2 is installed in the vehicle 3. The navigation device 2 displays a map around the vehicle position based on the stored map data, displays the current position of the vehicle on the map image, and is set using probe statistical information distributed from the probe center 4. This is an in-vehicle device that searches and guides a route to a destination. The details of the navigation device 2 will be described later.

  Next, the configuration of the probe center 4 constituting the route search system 1 will be described in more detail with reference to FIG.

  As shown in FIG. 2, the probe center 4 basically includes a server 11, a probe information DB 12 as information recording means connected to the server 11, a probe statistical information DB 13, and a center communication device 14. .

  The server 11 is an electronic control unit that performs various controls in the probe center 4. Then, the CPU 21 as the arithmetic device and the control device, the RAM 22 used as a working memory when the CPU 21 performs various arithmetic processes, the control program, and the route search processing in the navigation device 2 based on the collected probe information. And an internal storage device such as a ROM 23 in which a probe information maintenance program (FIG. 5), a reference calculation processing program (FIG. 7), and the like, which will be described later, for calculating a cost value calculation standard when performing the above are stored. The server 11 constitutes various means as processing algorithms together with a navigation ECU 33 described later. For example, the point setting means sets the starting point and the destination of the vehicle. The route information acquisition means acquires route information for specifying a route that has traveled from the departure point to the destination where the same vehicle has been set in the past. The search reference setting unit is configured to route the route searched by the route search process from the departure point to the destination based on the route information acquired by the route information acquisition unit so as to be closest to the route specified by the route information. Sets the calculation criteria for the cost value in the search process.

  The probe information DB 12 is a storage unit that cumulatively stores probe information collected from each vehicle 3 traveling throughout the country. In the present embodiment, the probe information collected from the vehicle 3 includes (a) the date and time, (b) the ID that identifies the vehicle from which the probe information is transmitted, (c) the departure point, and (d) the destination. (E) Information related to the link train on which the vehicle 3 has traveled is included. However, the probe information does not necessarily include all the information related to (a) to (e), and may include only information related to (b) to (e), for example.

  Hereinafter, probe information stored in the probe information DB 12 will be described in more detail with reference to FIG. FIG. 3 is a diagram showing an example of probe information stored in the probe information DB 12.

  As shown in FIG. 3, the probe information includes information on the above (a) to (e). For example, in the probe information shown in FIG. 3, the vehicle 3 with ID “101” starts traveling from the departure place A at 10:00: 00 on October 10, 2014, and links a, b, b It is stored that the vehicle travels in the order of c and link d and travels to the destination B. Similarly, other probe information is also stored in the present embodiment. The probe information is collected from the vehicle 3 that has traveled without using the route guidance function (the function of guiding so as to travel along the set route). For example, a point where the engine or the ACC power source is turned off is specified as the point where the is turned on and the destination.

  And the probe center 4 specifies the calculation reference | standard of the cost value at the time of performing the route search process in the navigation apparatus 2 for every vehicle by statistics of the probe information memorize | stored in probe information DB12. More specifically, a cost coefficient for reflecting the user's preference (a coefficient for adjusting the cost by adding or adding to the search cost in the route search process) is specified. Details regarding the specification of the cost value calculation criteria will be described later. And the information regarding the calculation reference | standard of the specified cost value is memorize | stored in probe statistical information DB13.

  Then, the probe center 4 distributes the probe statistical information stored in the probe statistical information DB 13 to the navigation device 2 in response to a request from the navigation device 2. On the other hand, the navigation apparatus 2 to which the probe statistical information is distributed executes various processes such as a route search process using the distributed probe statistical information.

  The center communication device 14 is a communication device for communicating with the vehicle 3 and the VICS (registered trademark) center via the network 15. In the present embodiment, probe information and distribution information are transmitted to and received from each vehicle 3 via the center communication device 14.

  Next, a schematic configuration of the navigation device 2 mounted on the vehicle 3 will be described with reference to FIG. FIG. 4 is a block diagram showing the navigation device 2 according to this embodiment.

  As shown in FIG. 4, the navigation device 2 according to the present embodiment includes a current position detection unit 31 that detects the current position of the vehicle 3 on which the navigation device 2 is mounted, and a data recording unit 32 that records various data. The navigation ECU 33 that performs various arithmetic processes based on the input information, the operation unit 34 that receives an operation from the user, and a map that is searched for by the user in a map around the vehicle and a route search process that will be described later. A liquid crystal display 35 that displays route information, a speaker 36 that outputs voice guidance related to route guidance, a DVD drive 37 that reads a DVD as a storage medium, a probe center 4 and VICS (registered trademark: Vehicle Information and Communication System). A communication module 38 for communicating with an information center such as a center. To have.

Below, each component which comprises the navigation apparatus 2 is demonstrated in order.
The current position detection unit 31 includes a GPS 41, a vehicle speed sensor 42, a steering sensor 43, a gyro sensor 44, 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 42 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 33. And navigation ECU33 calculates the rotational speed and moving distance of a driving wheel by counting the pulse which generate | occur | produces. In addition, it is not necessary for the navigation device 2 to include all of the four types of sensors, and the navigation device 2 may include only one or more of these types of sensors.

  The data recording unit 32 reads out an external storage device and a hard disk (not shown) as a recording medium, a map information DB 45, a distribution information DB 46, a predetermined program, and the like recorded on the hard disk, and stores predetermined data on the hard disk. And a recording head (not shown) as a driver for writing. The data recording unit 32 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 45 includes, for example, link data regarding roads (links), node data regarding node points, branch point data regarding each branch point, point data regarding points such as facilities, map display data for displaying a map, The storage means stores search data for searching for a route, search data for searching for a point, and the like.

  As described later, 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, a cost that is quantified as a route to an intersection (node) (hereinafter referred to as an intersection cost) or a cost that is quantified as a route to a link constituting a road (hereinafter referred to as a link cost). The 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 presence or absence of a traffic light, the travel route of the vehicle when passing through the intersection (that is, straight, right and left turns) 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. Based on the link length, in addition to the road attribute, road type, road width, and number of lanes of the link, the congestion information And the cost coefficient for reflecting the user's preference calculated by the probe center 4 is calculated.

  The distribution information DB 46 is a storage unit in which distribution information distributed from the probe center 4 is stored. The map information DB 45 and the distribution information DB 46 may be stored in an external server and acquired by the navigation device 2 through communication.

  On the other hand, the navigation ECU (Electronic Control Unit) 33 is an electronic control unit that controls the entire navigation device 2. The CPU 51 as an arithmetic device and a control device, and a working memory when the CPU 51 performs various arithmetic processes. Read out from the ROM 53 and the ROM 53 in which a route search processing program (FIG. 13) and the like to be described later are recorded in addition to the RAM 52 and the control program for storing the route data when the route is searched. An internal storage device such as a flash memory 54 for storing the program is provided.

  The operation unit 34 is operated when inputting a departure point as a travel start point and a destination point as a travel end point, and includes a plurality of operation switches (not shown) such as various keys and buttons. Then, the navigation ECU 33 performs control to execute various corresponding operations based on switch signals output by pressing the switches. The operation unit 34 can also be configured by a touch panel provided on the front surface of the liquid crystal display 35. Moreover, it can also be comprised with a microphone and a speech recognition apparatus.

  Further, the liquid crystal display 35 has 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. Instead of the liquid crystal display 35, HUD or HMD may be used.

  In addition, the speaker 36 outputs voice guidance for guiding traveling along the guidance route based on an instruction from the navigation ECU 33 and traffic information guidance.

  The DVD drive 37 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 45 is updated, and the like. A card slot for reading / writing a memory card may be provided in place of the DVD drive 37.

  The communication module 38 is a communication device for receiving information such as traffic jam information, regulation information, and traffic accident information transmitted from a traffic information center such as the VICS (registered trademark) center or the probe center 4. For example, a mobile phone or DCM is applicable. It is also used for transmitting and receiving probe information and distribution information to and from the probe center 4.

  Next, a probe information maintenance program executed by the CPU 21 in the server 11 of the probe center 4 configuring the route search system 1 according to the present embodiment having the above configuration will be described with reference to FIG. FIG. 5 is a flowchart of the probe information maintenance program according to this embodiment. Here, the probe information maintenance program is executed at a predetermined time interval (for example, every 24 hours), and the collected probe information is used as a preparation for calculating a cost value calculation standard based on the probe information collected from each vehicle 3. It is a program to be maintained. Note that the programs shown in the flowcharts of FIGS. 5 and 7 below are stored in the RAM 22 and the ROM 23 provided in the server 11 and executed by the CPU 21.

  Here, in the probe information maintenance program, the probe information is maintained separately for each vehicle, each region, and each time zone. Therefore, the following steps (hereinafter abbreviated as S) 1 and subsequent steps are repeatedly executed for each vehicle to be classified, each region, and each time zone. The area may be a unit of administrative division such as a municipality or a unit of mesh. Also, the time zone is, for example, 3 hours or 6 hours. As a result, the probe information is divided and maintained for each region and for each time zone (for example, 7:00 to 10:00, 10: 0 to 13:00, etc.). The configuration may be executed for each time zone and for each day of the week.

  First, in S1, the CPU 21 extracts probe information corresponding to the region and time zone to be processed from the probe information (FIG. 3) stored in the probe information DB 12. For example, in the case where the maintenance of the probe information is performed from 7:00 to 10:00 in the city A of the vehicle A, the vehicle A has a travel history of traveling in the city A from 7:00 to 10:00. Probe information is extracted from the probe information DB 12.

  Next, in S2, the CPU 21 extracts a travel locus (route) of a vehicle to be processed (hereinafter referred to as a processing target vehicle) from the probe information acquired in S1. Specifically, the travel locus is information for identifying the departure point, the destination, and the link train that has traveled from the departure point to the destination. Since the travel locus is extracted for each probe information, if 100 pieces of probe information are acquired in S1, 100 travel tracks are extracted. Further, in the present embodiment, as described above, the vehicle that has traveled from the departure point to the destination without using the route guidance function (the function of performing guidance along the set route) by the navigation device 2 or the like. 3 to collect probe information. Accordingly, what is extracted in S2 is the travel locus of the processing target vehicle that has traveled without using the route guidance function.

  Subsequently, in S3, the CPU 21 sets an evaluation point and an evaluation point for the travel locus extracted in S2. Specifically, the CPU 21 first sets one evaluation point at a time between intersections included in the travel locus (except for intersections with narrow streets). Next, a score obtained by dividing 100 points by the number of set evaluation points is set as an evaluation point for each evaluation point. Therefore, for example, as shown in FIG. 6, when five intersections A to E are included in the travel locus, the first evaluation point is set at the link a between the intersection A and the intersection B, and the intersection B and A second evaluation point is set for the link b between the intersections C, a third evaluation point is set for the link c between the intersections C and D, and a fourth e is set for the link e between the intersections D and E. The evaluation point is set. Then, 25 evaluation points are set for each of the first to fourth evaluation points.

  The evaluation point may be set at an intermediate point between the intersections, or may be set near one of the intersections. Moreover, you may change the evaluation score set to an evaluation point for every point, without making it the same score. For example, the first evaluation point may be set to 30 points, and the second evaluation point may be set to 10 points. Then, the CPU 21 sets the evaluation point and the evaluation point for all the travel trajectories extracted in S2.

  Thereafter, in S4, the CPU 21 stores the travel locus extracted in S2 in the DB as reference data in association with the evaluation point and the evaluation point set in S3. The reference data stored in S4 is used when calculating a cost value calculation reference when performing a route search process in the navigation device 2 as described later.

  Next, a reference calculation processing program executed by the CPU 21 in the server 11 of the probe center 4 constituting the route search system 1 will be described with reference to FIG. FIG. 7 is a flowchart of the reference calculation processing program according to the present embodiment. Here, the reference calculation processing program is executed when the route searching process is executed in the navigation device 2, and the route searching is performed in the navigation device 2 using the reference data created in the probe information maintenance program (FIG. 5). It is a program for calculating a calculation standard for cost values for each vehicle. In the present embodiment, an annealing method, which is one of algorithms for deriving an optimal solution, is used when calculating a cost value calculation reference in the reference calculation processing program.

  First, in S <b> 11, the CPU 21 acquires information for specifying the departure point and the destination specified in the route search process (FIG. 13) executed in the navigation device 2 together with information for specifying the transmission source vehicle 3. The departure point is, for example, the current position of the user (vehicle) of the navigation device 2 or an arbitrary point (for example, home) designated by the navigation device 2 by the user. The destination corresponds to a facility or the like designated by the navigation device 2 by the user.

  Next, in S12, the CPU 21 generates the reference data relating to the travel locus of the vehicle that acquired the departure place and the destination in S11 from the reference data created in the above-described probe information maintenance program (FIG. 5) and stored in the DB. In addition, reference data relating to a traveling locus having the same starting point and destination as the starting point and destination acquired in S11 is extracted.

  Subsequently, in S13, the CPU 21 initializes a temperature parameter T used in the annealing method. The temperature parameter T is a parameter that defines the probability of updating the parameter even when the score does not improve in the annealing method as will be described later, and the initial value is, for example, 100 degrees (probability 100%). The temperature parameter T is stored in a memory such as the RAM 22.

  Thereafter, in S14, the CPU 21 defines a parameter P for each road attribute, and substitutes an initial value for the value of each parameter P. The parameter P corresponds to a cost coefficient (a coefficient for adjusting the cost by adding or adding to the search cost in the route search process). Here, FIG. 8 is a diagram showing an example of the parameter P (cost coefficient) defined in S14. In the example shown in FIG. 8, “road type”, “number of lanes”, “width”, “number of installed traffic lights”, “number of adjacent intersections”, “ A total of six types of “the number of adjacent facilities of a specific type” are set. Note that the type and number of road attributes that define the parameters can be set as appropriate.

In the example shown in FIG. 8, parameters P _{11 to} P ₆₄ are defined for each of the six types of road attributes. For example, the parameter P ₁₃ is defined for the road type “National road”, and the parameter P ₅₁ is defined for the difference number “0 (intersection is not adjacent)” of adjacent intersections. The initial value to be substituted for the parameter P can be selected as appropriate. For example, as shown in FIG. 9, “1” is substituted for all of P _{11 to} P ₆₄ . A different value for each of P _{11 to} P ₆₄ can be substituted as an initial value.

Subsequently, in S15, the CPU 21 randomly changes any one of the parameters P defined in S14 to a new value. The parameter P to be changed to a new value can be arbitrarily selected. The number of parameters to be changed may be one or two or more. Further, the value of the new parameter P after the change may be a value for increasing the current parameter P or a value for decreasing the current parameter P. Furthermore, it is possible to set as appropriate how much the current parameter P is displaced (for example, +0.1, -0.5, +1, etc.). For example, in the example shown in FIG. 10, the parameter P ₁₃ for the road type “city highway” is changed from “1” by 0.1 to “0.9”.

  Thereafter, the processing after S16 is executed using the value of each parameter P after being changed at S15. However, at the time of the first execution, the processing after S16 is executed using the parameter P of the initial value substituted at S14 without executing the processing at S15.

  The subsequent processes of S16 to S18 are executed for all the reference data (running locus) extracted in S12. And after performing the process of S16-S18 by making all the reference data (running locus | trajectory) into object, it transfers to S19.

  First, in S16, the CPU 21 acquires reference data to be processed from the DB. Note that the reference data includes a travel locus, an evaluation point set for the travel locus, and an evaluation point as described above (see FIG. 6).

  Next, in S17, the CPU 21 performs a route search process from the departure point to the destination acquired in S11 using the parameter P (cost factor) defined in S14, and specifies one recommended route. In addition, when the parameter P is updated in S20 and S21 described later, the statistical information is calculated using the latest parameter P after the update. For the parameter P changed to a new value in S15, statistical information is calculated using the changed parameter P. The route search process of S17 is performed using a known Dijkstra method.

Specifically, the recommended route is specified by the following processing.
First, the CPU 21 calculates the link cost of each link to be searched using the link length of the link and the parameter P. The link cost is calculated as statistical information by the following equation (1).
Link cost = link length L of search target link × parameter of road type corresponding to search target link (any of P _{11 to} P ₁₄ ) × parameter of number of lanes corresponding to search target link (any of P _{21 to} P ₂₄ ) X) Parameter of the corresponding width of the search target link (any of P _{31 to} P ₃₃ ) + Parameter of the number of traffic signals corresponding to the search target link (any of P _{41 to} P ₄₂ ) + Corresponding of the search target link the difference channel number of parameters + search target link corresponding POI number of parameters _(either P 51 _{to P 54) (either P 61 ~P 64) ···· (1} )
The equation (1) is a calculation equation when the parameters P _{11 to} P ₆₄ shown in FIG. 8 are defined as parameters for the road attribute in S14. It should be noted that whether each parameter P is integrated or added to the link length can be changed as appropriate. For example, parameters to be taken into account according to the length of the link length are integrated, and parameters independent of the link length are added.
Further, the CPU 21 quantifies the search cost other than the link cost calculated by the above formula (1), for example, the intersection cost obtained by quantifying the appropriate degree as a route to the intersection (node) and the cost required for traveling. The calculated fee cost is also calculated. Then, a route that minimizes the total of the calculated search costs is set as a recommended route.

  Subsequently, in S18, the CPU 21 compares the travel locus of the reference data acquired in S16 with the recommended route searched in S17, and calculates the degree of coincidence as a score. Specifically, the sum of the evaluation points set in the evaluation points in the route range that coincides with the recommended route in the travel locus is calculated as a score. For example, in the example shown in FIG. 11, the travel locus and the recommended route coincide with each other in the link a and the link d, and the total of the evaluation points set at the two evaluation points of the link a and the link d is 50. Points are calculated as scores. The larger the score, the closer the recommended route calculated based on the parameter P is closer to the route on which the vehicle has actually traveled in the past, that is, the parameter P has a more appropriate value.

  Thereafter, in S19, the CPU 21 calculates the total value of the scores calculated for each reference data in S16 to S18, and the total value calculated before changing the parameter P in S15 (that is, S19 executed last time). It is determined whether or not it has become larger than the total value calculated in the process (1). Note that the average value, the median value, and the maximum value may be compared instead of the total value. When the recommended route is specified at the first execution, that is, when only the initial value of the parameter P is specified in S17, the process returns to S15 without performing the processes after S19.

  And when it determines with the total value of a score becoming larger than the value calculated last time (S19: YES), it transfers to S20. On the other hand, when it is determined that the total value of the scores is equal to or smaller than the previously calculated value (S19: NO), the process proceeds to S21.

In S20, the CPU 21 recognizes that the value of the new parameter P changed in S15 is more appropriate than before the change, and updates the parameter P to the value after the change. For example, in the example illustrated in FIG. 10, the parameter P ₁₃ for the road type “city highway” is updated to “0.9”. Thereafter, the process proceeds to S22.

On the other hand, in S21, the CPU 21 determines that the value of the new parameter P changed in S15 is more inappropriate than before the change. Then, the parameter P is updated to the changed value determined to be inappropriate with the probability based on the current value of the temperature parameter T. For example, in this embodiment, the temperature parameter T is changed in units of 1 degree from 100 degrees to 0 degrees. Then, the parameter of S21 is updated with a probability of 100% if it is 100 degrees and 50% if it is 50 degrees. If it is determined not to update, the value of the parameter P changed in S15 is returned to the value before the change. For example, if it is determined not to update the above S21 in the example shown in FIG. 10, parameters P ₁₃ of the road type "Urban Expressway" is returned to "1" before the change. Thereafter, the process proceeds to S22.

  In S22, the CPU 21 reads the current temperature parameter T from the memory and updates it to a new value. In this embodiment, the initial value is set to 100 degrees, and the value is subtracted by 1 degree.

  Next, in S23, the CPU 21 reads the current temperature parameter T from the memory, and determines whether or not the temperature parameter T has become 0 degrees.

  When it is determined that the temperature parameter T has become 0 degrees (S23: YES), the process proceeds to S24. On the other hand, when it is determined that the temperature parameter T is not 0 degree (S23: NO), the process returns to S15. Thereafter, any one of the parameters P is randomly changed to a new value again, and the processes after S16 are executed. And as a result of repeating the process of S15-S22 until the temperature parameter T becomes 0 degree | times, finally the optimal value of parameter P (cost factor) is specified as shown in FIG. Note that the optimum value of the parameter P (cost factor) is set so that the route searched by the route search process is closest to the route on which the host vehicle has actually traveled from the same starting point to the destination in the past. This is a calculation standard for the cost value.

  Thereafter, in S24, the CPU 21 sets the parameter P (cost factor) of the optimum value finally identified as a result of executing the processes of S11 to S23 as a calculation reference for the cost value in the route search process. To the navigation device 2 (the navigation device that acquired the starting point and the destination in S11). The navigation device 2 executes a route search process for searching for a recommended route using the parameter P (cost factor) of the optimum value transmitted from the probe center 4 as will be described later.

  Next, a route search processing program executed by the CPU 51 in the navigation device 2 configuring the route search system 1 according to the present embodiment will be described with reference to FIG. FIG. 13 is a flowchart of the route search processing program according to this embodiment. Here, the route search processing program is a program that is executed when a predetermined operation for performing a route search is received in the navigation device 2 and searches for a recommended route from the departure point to the destination. Note that the program shown in the flowchart of FIG. 13 below is stored in the RAM 52 or ROM 53 provided in the navigation device 2 and is executed by the CPU 51.

  First, in S <b> 31 in the route search processing program, the CPU 51 acquires a departure place and a destination. Note that the departure point may be the current position of the vehicle or an arbitrary point (for example, a home) designated by the user. The destination is acquired based on a user operation (for example, a facility search or selection operation) received by the operation unit 34.

  Next, in S32, the CPU 51 transmits the departure place and destination acquired in S31 to the probe center 4. As a result, the above-described reference calculation processing program (FIG. 7) is executed in the probe center 4.

  Thereafter, in S33, the CPU 51 obtains the parameter P (cost factor) of the optimum value finally specified by communication from the probe center 4 as a result of executing the above-described reference calculation processing program (FIG. 7) in the probe center 4. To do.

  Subsequently, in S34, the CPU 51 performs a route search process from the departure point to the destination acquired in S31 using the parameter P (cost factor) of the optimum value acquired in S33. Specifically, a known Dijkstra method is used, and a route having a minimum cost value is set as a recommended route. In addition to the recommended route, other candidate routes whose search conditions are changed (for example, a route searched with distance priority, general road priority, and toll road priority) may be searched.

Specifically, the recommended route is specified by the following processing.
First, the CPU 51 calculates the link cost of each link to be searched using the link length of the link and the parameter P. In addition, statistical information is calculated by the following formula | equation (2) about a link cost.
Link cost = link length L of search target link × parameter of road type corresponding to search target link (any of P _{11 to} P ₁₄ ) × parameter of number of lanes corresponding to search target link (any of P _{21 to} P ₂₄ ) X) Parameter of the corresponding width of the search target link (any of P _{31 to} P ₃₃ ) + Parameter of the number of traffic signals corresponding to the search target link (any of P _{41 to} P ₄₂ ) + Corresponding of the search target link the difference channel number of parameters + search target link corresponding POI number of parameters _(either P 51 _{to P 54) (either P 61 ~P 64) ···· (2} )
The equation (2) is a calculation equation when the parameters P _{11 to} P ₆₄ shown in FIG. 8 are defined as parameters for the road attribute in S14. It should be noted that whether each parameter P is integrated or added to the link length is the same as in the equation (1).
Further, the CPU 51 quantifies the search cost other than the link cost calculated by the above formula (2), for example, the intersection cost obtained by quantifying the appropriate degree as a route to the intersection (node), and the cost required for traveling. The calculated fee cost is also calculated. Then, a route that minimizes the total of the calculated search costs is set as a recommended route.

  Thereafter, in S35, the CPU 51 guides the recommended route searched in S34 to the user via the liquid crystal display 35 or the like. Then, the recommended route guided based on the subsequent user operation is set as the guide route of the navigation device 2, and travel guidance based on the set guide route is performed.

  Note that not the navigation device 2 but the probe center 4 performs the route search process (S34) using the parameter P (cost factor) of the optimum value and distributes the searched recommended route to the navigation device 2. Also good. In that case, it is not necessary to distribute the parameter P having the optimum value to the navigation device 2.

  As explained in detail above, in the route search system 1 according to the present embodiment, the route search method by the route search system 1 and the computer program executed by the route search system 1, each vehicle 3 traveling in the whole country in the probe center 4. While collecting route information specifying the route traveled as probe information, the starting point and destination set in the route search process of the navigation device 2 are acquired (S11), and the route search process is performed from the collected probe information. Route information when the vehicle has traveled from the same departure point to the destination in the past is extracted (S12), and the route searched by the route search process from the departure point to the destination is the route specified by the route information. Since the calculation standard of the cost value in the route search process is set so as to be closest (S13 to S24), the past Vehicle it is possible to set a calculation reference of the cost values as path close to the actual travel route until the destination is searched from the same departure point. As a result, it is possible to search for an appropriate route that more closely matches the user's preference, reflecting the user's preference on a route basis, not on a link basis, and taking into account the departure point and destination.

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 cost coefficient for calculating the link cost is defined as the parameter P for calculating the optimum value, but the cost coefficient for calculating the intersection cost may be defined. In that case, the parameter P is defined not for the road attribute but for the intersection attribute (for example, the number of difference roads, the presence / absence of a traffic light, the road type of the road to be connected, the presence / absence of a right turn lane, etc.). The optimum value of the cost coefficient is calculated. In the route search process (FIG. 13), the intersection cost is specified using the calculated optimum parameter P (cost factor), and the recommended route is searched.

  In this embodiment, the annealing method is used as an algorithm for deriving the optimum value of the parameter P. However, other algorithms such as mountain climbing and tabu search may be used.

  In this embodiment, the road attributes that define the parameter P are “road type”, “number of lanes”, “width”, “number of installed traffic lights”, “number of adjacent intersections”, “adjacent” Although a total of six types of “number of specific types of facilities to be performed” are set, it is not necessary to define parameters for all six types, and only one type or two to five types may be used.

  Further, in the present embodiment, the probe information has been described as an example of information for acquiring the travel locus of the vehicle, but information other than the probe information may be used. For example, each vehicle stores a past travel history in a DB included in the host vehicle, and when performing a route search, the past travel history of the host vehicle is acquired from the DB, and an optimum value parameter P is obtained from the acquired travel history. It is good also as a structure which calculates (cost coefficient). In this case, the probe center 4 is not necessary in the route search system 1, and the route search system 1 can be configured by only the navigation device 2.

  In the present embodiment, the execution subject of the probe information maintenance program shown in FIG. 5 and the reference calculation processing program shown in FIG. 7 is the server 11 of the probe center 4, but the navigation device 2 executes part or all of it. It is good also as a structure. Further, instead of the navigation device 2, the route search system 1 can be configured by another device having a route search function. For example, a mobile phone, a smart phone, a tablet terminal, a personal computer, etc. are possible.

  Moreover, although the embodiment which actualized the route search system according to the present invention has been described above, the route search system can also have the following configuration, and in that case, the following effects can be obtained.

For example, the first configuration is as follows.
Route setting means for setting a starting point and a destination of a vehicle, and route information for acquiring route information for specifying a route that the vehicle has traveled from the starting point to the destination in the past set by the point setting unit. Based on the route information acquired by the acquisition unit and the route information acquisition unit, the route searched by the route search process from the departure place to the destination is closest to the route specified by the route information. have a, a search criterion setting means for setting a calculation reference of the cost value in the route search processing as the calculation reference of the cost value is a cost factor that is defined for each road attribute, the from the departure point In the route search process to the destination, the cost value of the search target link, which is a link to be searched by the route search process from the departure place to the destination, Calculated using a cost coefficient corresponding to the road attribute of the search target link, specifies a route based on the calculated cost value, the search criterion setting means defines the cost coefficient as a parameter for each road attribute, The optimum value of the parameter for each road attribute is specified by comparing and evaluating the route searched based on the changed parameter and the route specified by the route information, and for each specified road attribute An optimal parameter value is set as a calculation reference for the cost value .
According to the route search system having the above-described configuration, the cost value calculation standard is set so that a route close to the route in which the vehicle has actually traveled from the same starting point to the destination in the past is searched. It is possible to reflect the user's preference in units of routes instead of units. Therefore, it is possible to search for an appropriate route in accordance with the user's preference in consideration of the departure point and the destination.

Further, according to the route searching system having an upper Symbol configuration, since the path close to the actual traveling route of the vehicle from the same departure point in the past to the destination to correct the cost value of the link to be searched It is possible to specify the cost coefficient. As a result, it is possible to perform an appropriate route search corresponding to various road attribute links using the cost coefficient.

The second configuration is as follows.
The search criteria setting unit, and identifies the optimum value of the parameter for each road attribute using the law we Na can burn.
According to the route search system having the above configuration, it is possible to specify the optimum value of the parameter defined for each road attribute by the annealing method, and it is possible to perform an appropriate route search in consideration of the road attribute.

The third configuration is as follows.
The search criterion setting means, wherein the evaluation point with respect to the path identified by the path information set multiple, pre Symbol search every parameter is varied while varying the value of the parameter by the route search processing using the parameters An evaluation score is calculated according to the number of evaluation points included in a section in which the determined route and the route specified by the route information coincide with each other, and the value of the parameter with the highest total evaluation score is set as the parameter value. It is specified as an optimum value.
According to the route search system having the above configuration, it is possible to appropriately evaluate the degree of coincidence of a plurality of routes using evaluation points, and the host vehicle actually travels from the same starting point to the destination in the past. It is possible to more accurately specify the optimum value of the cost coefficient for searching for a route close to the route.

The fourth configuration is as follows.
The search criteria setting means defines at least one or more of the road type, the number of lanes, the width, the number of installed traffic lights, the number of adjacent intersections, and the number of adjacent specific types of facilities as the road attributes. It is characterized by.
According to the route search system having the above configuration, a route close to the route in which the host vehicle actually traveled from the same starting point to the destination in the past is searched by considering various road attributes of the link. It is possible to more accurately estimate the cost coefficient.

The fifth configuration is as follows.
The route information acquisition means acquires the route information when the vehicle travels from the departure place to the destination without using a route guidance function for performing guidance along a set route. And
According to the route search system having the above configuration, it is possible to acquire route information of a route reflecting the user's preference. Therefore, it is possible to set a cost value calculation standard for searching for an appropriate route according to the user's preference.

DESCRIPTION OF SYMBOLS 1 Route search system 2 Navigation apparatus 3 Vehicle 4 Probe center 11 Server 21 CPU
22 RAM
23 ROM
33 Navigation ECU
51 CPU
52 RAM
53 ROM

Claims (7)

Point setting means for setting the starting point and destination of the vehicle;
Route information acquisition means for acquiring route information for specifying a route in which the vehicle has traveled from the departure place to the destination set by the point setting means in the past;
Based on the route information acquired by the route information acquisition means, the route searched by the route search process from the departure place to the destination is closest to the route specified by the route information. a search criterion setting means for setting a calculation reference of the cost value in the search process, the possess,
The calculation standard of the cost value is a cost coefficient defined for each road attribute,
In the route search process from the departure place to the destination, the cost value of the search target link, which is a link to be searched by the route search process from the departure place to the destination, is used as the road attribute of the search target link. Calculate using the corresponding cost factor, identify the route based on the calculated cost value,
The search criterion setting means includes
Specify the cost factor as a parameter for each road attribute,
The optimal value of the parameter for each road attribute is specified by comparing and evaluating the route searched based on the changed parameter and the route specified by the route information while changing the parameter,
A route search system , wherein an optimum value of the parameter for each identified road attribute is set as a calculation reference for the cost value . The search criteria setting unit, the route search system according to claim 1, wherein the identifying the optimum value of the parameter for each road attribute using the law we Na can burn. The search criterion setting means includes
Set multiple evaluation points for the route specified by the route information,
The number of evaluation points included in the matching section between the route specified by the route search the route information and the search route by treatment with the parameters before Symbol each parameter was varied while changing the value of the parameter The evaluation score is calculated accordingly,
3. The route search system according to claim 1 , wherein a value of the parameter having the highest total evaluation score is specified as an optimum value of the parameter. The search criterion setting means includes
Road type, number of lanes, road width, the number of the installed traffic signal, the difference between passage number of adjacent intersections, characterized by defining at least one or more number of specific types of facilities adjacent as the road attribute claim 1 The route search system according to claim 3 . The route information acquisition means acquires the route information when the vehicle travels from the departure place to the destination without using a route guidance function for performing guidance along a set route. The route search system according to any one of claims 1 to 4 . A point setting means for setting a starting point and a destination of the vehicle;
A step of acquiring route information for specifying a route in which the vehicle has traveled from the starting point to the destination set in the past by the point setting unit;
Based on the route information acquired by the route information acquisition unit, a search reference setting unit searches for a route searched by the route search process from the departure place to the destination as a route specified by the route information. possess and setting a calculation reference of the cost value in the route search processing as closest and,
The calculation standard of the cost value is a cost coefficient defined for each road attribute,
In the route search process from the departure place to the destination, the cost value of the search target link, which is a link to be searched by the route search process from the departure place to the destination, is used as the road attribute of the search target link. Calculate using the corresponding cost factor, identify the route based on the calculated cost value,
The search criterion setting means includes
Specify the cost factor as a parameter for each road attribute,
The optimal value of the parameter for each road attribute is specified by comparing and evaluating the route searched based on the changed parameter and the route specified by the route information while changing the parameter,
A route search method , wherein an optimum value of the parameter for each identified road attribute is set as a calculation reference for the cost value . Computer
Point setting means for setting the starting point and destination of the vehicle;
Route information acquisition means for acquiring route information for specifying a route in which the vehicle has traveled from the departure place to the destination set by the point setting means in the past;
Based on the route information acquired by the route information acquisition means, the route searched by the route search process from the departure place to the destination is closest to the route specified by the route information. A search criterion setting means for setting a calculation criterion for a cost value in the search process;
A computer program to make it function ,
The calculation standard of the cost value is a cost coefficient defined for each road attribute,
In the route search process from the departure place to the destination, the cost value of the search target link, which is a link to be searched by the route search process from the departure place to the destination, is used as the road attribute of the search target link. Calculate using the corresponding cost factor, identify the route based on the calculated cost value,
The search criterion setting means includes
Specify the cost factor as a parameter for each road attribute,
The optimal value of the parameter for each road attribute is specified by comparing and evaluating the route searched based on the changed parameter and the route specified by the route information while changing the parameter,
The computer program which sets the optimal value of the said parameter for every specified road attribute as a calculation reference | standard of the said cost value .

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