JP2015197341A - Route search system and terminal equipment, route search method and information processing method, and route search program and information processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a route search system capable of searching a desired route by autonomously and appropriately selecting a region in which a radio wave receiving condition for information acquisition is better.SOLUTION: A route search system SS that searches a route along which a vehicle moves and which includes plural links includes an interface 1 that acquires for each region electric field intensity data which represents a radio wave receiving condition in the vehicle, and a searcher 2 that searches a route on the basis of the acquired electric field intensity data in such a manner that links in a region in which the radio wave receiving condition is worse than any other region can be hardly searched as part of a route compared with links in any other region.

Description

  The present application belongs to a technical field of a route search device and a terminal device, a route search method and an information processing method, a route search program, and an information processing program. More specifically, the present invention belongs to a technical field of a route search device and a terminal device for searching for a route to be moved by a mobile body, a route search method and an information processing method, and a program for each of the route search device and the terminal device.

  In recent years, navigation devices that guide the movement of vehicles such as automobiles, bicycles, rail cars, or people to destinations have become widely used. The route needs to be set appropriately. Regarding this point, there is a technique described in Patent Document 1 below as an example of a conventional technique for setting a route for a vehicle.

  In the technique described in Patent Document 1, data indicating whether communication is possible on the spot is collected / obtained from a large number of users, and a route search is performed in consideration of the communication status based on the data. Yes.

JP 2004-096267 A

  However, the above Patent Document 1 does not disclose how to specifically perform a route search based on data indicating whether communication is possible. Furthermore, in the technique described in Patent Document 1, for an area where data indicating whether or not communication can be obtained from the user in the past, a route search based on the data can be performed. For areas where acquisition of information is not possible (that is, areas where communication availability is unknown), a route that takes into account the desired communication status, unless the information of the content corresponding to the data is separately provided from, for example, a communication provider There is also a problem that the search cannot be performed.

  Therefore, the present application has been made in view of the above problems, and an example of the problem is to automatically select a region where the reception status of information acquisition radio waves is better and appropriately select a desired route. The object is to provide a route search device and a terminal device that can be searched, a route search method and an information processing method, and a program for each of the route search device and the terminal device.

  In order to solve the above-described problem, the invention according to claim 1 is a travel route along which a moving body such as a vehicle moves, and includes a search for a travel route including at least one of a plurality of travel routes or travel points. In the route search apparatus, an acquisition unit such as an interface that acquires reception status information indicating reception status of radio waves in the mobile body for each region, and the reception status is transferred to another region based on the acquired reception status information. The travel route is searched such that the at least one in a relatively poor reception area is less likely to be searched as part of the travel route than the at least one in the other region. And a search means such as a search unit.

  In order to solve the above-described problem, an invention according to claim 7 is a terminal device provided in a moving body such as a vehicle, and an electric field intensity calculation unit that detects a reception state of radio waves in the moving body for each region. Detection means, output means such as an interface for outputting reception status information indicating the detected reception status to the outside, and a moving path of the moving body including at least one of a plurality of moving paths or moving points And a route information acquisition means such as an interface for acquiring travel route information indicating a travel route searched based on the output reception status information, wherein the received travel status is other than the received travel status. The at least one in a relatively bad area relative to the other area is searched as a part of the travel route than the at least one in the other area. Configured to be moved the route searched as hard to be.

  In order to solve the above-mentioned problem, the invention according to claim 8 is a travel route on which a moving body such as a vehicle moves, and includes a search for a travel route including at least one of a plurality of travel routes or travel points. In the route search method executed by the route search device, the reception status is obtained based on the acquisition step of acquiring reception status information indicating the reception status of radio waves in the mobile body for each region, and the acquired reception status information. The at least one in the poor reception area relative to another area is less likely to be searched as part of the travel route than the at least one in the other area, and And a search step for searching for a movement route.

  In order to solve the above-described problems, the invention according to claim 9 is an information processing method executed in a terminal device provided in a moving body such as a vehicle. A detection step for detecting, an output step for outputting reception status information indicating the detected reception status to the outside, and a moving path of the moving body including at least one of a plurality of moving paths or moving points; A route information acquisition step of acquiring travel route information indicating a travel route searched based on the output reception status information, wherein the searched travel route has the reception status with respect to another region. The at least one in a relatively bad area is searched in such a way that it is less likely to be searched as a part of the movement route than the at least one in the other area. Configured to be moving path.

  In order to solve the above-described problem, the invention according to claim 10 is a travel route along which a moving body such as a vehicle moves, and includes a search for a travel route including at least one of a plurality of travel routes or travel points. And a computer included in the route search device for acquiring, for each region, reception status information indicating reception status of radio waves in the mobile body, and based on the acquired reception status information, the reception status is other than The travel route is configured such that the at least one in the poor reception area relatively with respect to the region is less likely to be searched as a part of the travel route than the at least one in the other region. It functions as a search means for searching.

  In order to solve the above-described problem, the invention according to claim 11 is a computer that includes a terminal device provided in a moving body such as a vehicle. Means for outputting the reception status information indicating the detected reception status to the outside, and a moving path of the moving body including at least one of a plurality of moving paths or moving points and the output An information processing program that functions as a route information acquisition unit that acquires travel route information indicating a travel route searched based on received reception status information, wherein the received travel status is other than The at least one in an area that is relatively bad with respect to the area is searched as a part of the travel route than the at least one in the other area. Configured to be a movement route searched by the hardly.

It is a block diagram which shows the schematic structure of the route search apparatus which concerns on embodiment. It is a block diagram which shows the schematic structure of the route search system which concerns on an Example. It is a block diagram which shows the structure of the broadcast receiving part in the navigation apparatus which concerns on an Example. It is a flowchart which shows the electric field strength measurement process which concerns on an Example. It is a flowchart which shows the electric field strength distribution data generation process which concerns on an Example. It is a flowchart which shows the electric field strength map production | generation process which concerns on an Example. It is a figure explaining the electric field strength map production | generation process etc. which concern on an Example, (a) is a figure which illustrates an electric field strength map, (b) is a figure which illustrates a connection stability map. It is a flowchart which shows the update process of the measured value estimated area which concerns on an Example. It is a figure which illustrates the update process of the measured value estimation area which concerns on an Example, (a) is a figure which shows a 1st example, (b) is a figure which shows a 2nd example. It is a figure which shows the 3rd example of the update process of the measured value estimated area which concerns on an Example. It is a flowchart which shows the route search process which concerns on an Example. It is the flowchart etc. which show the calculation process of the passage cost in the route search process which concerns on an Example, (a) is the said flowchart, (b) is a figure which illustrates a passage cost.

  Next, the form for implementing this application is demonstrated using FIG. FIG. 1 is a block diagram illustrating a schematic configuration of the route search apparatus according to the embodiment.

  As shown in FIG. 1, the route search apparatus S according to the embodiment is a moving route on which a moving body such as a vehicle, a bicycle, a train, or a person moves, and is at least one of a plurality of moving paths or moving points. In the route search device for searching for a movement route including, the acquisition means 1 and the search means 2 are provided. The moving path in this case is a moving path corresponding to, for example, a “link” in map data. The moving point is a moving point corresponding to a “node” in the map data.

  In this configuration, the acquisition unit 1 acquires reception status information indicating the reception status of radio waves in the mobile body for each region. The reception status information in this case is data indicating the electric field strength when a radio wave having a predetermined frequency is received at a predetermined location, for example.

  And the search means 2 is based on the reception status information acquired by the acquisition means 1, and the plurality of movement paths or movement points in the poor reception area where the radio wave reception status of the mobile body is relatively poor with respect to other areas The travel route is searched such that at least one of the travel routes is more difficult to be searched as a part of the travel route than at least one of the plurality of travel routes or travel points in the other area.

  As described above, according to the operation of the route search device S according to the embodiment, when searching for a moving route including a plurality of moving routes or moving points, based on the reception status information for each region, A travel route is searched such that a travel route or the like is less likely to be searched than a travel route or the like in another area. Therefore, for example, when it is desired to move by selecting a region where the reception status of the information acquisition radio wave is good, it is possible to automatically and appropriately select a region where the reception status is better and to search for a desired movement route.

  Next, specific examples corresponding to the above-described embodiment will be described with reference to FIGS. The embodiment described below is connected to a navigation device mounted on one or a plurality of vehicles as an example of the “moving body” according to the present application, and each navigation device via a network such as the Internet. This is an embodiment when the present application is applied to a route search system configured to search for a route along which each vehicle moves.

  2 is a block diagram illustrating a schematic configuration of the route search system according to the embodiment, FIG. 3 is a block diagram illustrating a configuration of a broadcast receiving unit in the navigation apparatus according to the embodiment, and FIG. It is a flowchart which shows the electric field strength measurement process which concerns. FIG. 5 is a flowchart showing the field strength distribution data generation processing according to the embodiment, FIG. 6 is a flowchart showing the field strength map generation processing according to the embodiment, and FIG. 7 shows the field strength map generation processing and the like. It is a figure explaining. Further, FIG. 8 is a flowchart showing the update process of the measurement value estimation area according to the embodiment, and FIGS. 9 and 10 are diagrams respectively illustrating the update process of the measurement value estimation area according to the embodiment. Furthermore, FIG. 11 is a flowchart showing a route search process according to the embodiment, and FIG. 12 is a flowchart showing a pass cost calculation process in the route search process according to the embodiment. At this time, in FIG. 2, the same member numbers as the respective constituent members in the route search apparatus S are used for the respective constituent members in the examples corresponding to the respective constituent members in the route search apparatus S according to the embodiment shown in FIG. 1. ing.

  As shown in FIG. 2, the route search system SS according to the embodiment is mounted on a vehicle, and the navigation device NV1, the navigation device NV2, the navigation device NV3,. Natural number) and a server device SV according to the embodiment, which is fixedly installed in a predetermined server center or the like. Here, in the following description, when the common items of the navigation device NV1, the navigation device NV2, the navigation device NV3,..., The navigation device NVn are described, they are simply referred to as “navigation device NV”. Each navigation device NV and the server device SV are configured to be able to exchange data with each other via the network NW.

  Next, each navigation device NV includes an interface 13, a processing unit 10 including a CPU, a RAM (Random Access Memory) and a ROM (Read Only Memory), a non-volatile HDD (Hard Disc Drive), a volatile memory, and the like. (Not shown) including a recording unit, a sensor unit 14, a GPS (Global Positioning System) receiving unit 15, an FM (Frequency Modulation) broadcast receiving unit 16, a broadcast receiving unit 17, a display 18 including a liquid crystal display, etc. And an operation unit 18 including an operation button and a remote controller. In addition, the navigation device NV may include a speaker for outputting guidance voice.

  On the other hand, the processing unit 10 includes an electric field intensity calculation unit 11 and a current position detection unit 12. At this time, the electric field intensity calculation unit 11 and the current position detection unit 12 may be realized by a so-called hardware logic circuit constituting the processing unit 10, or a route search according to the present application described later for the navigation device NV. The program may be realized by software by the CPU of the processing unit 10 reading and executing the business program. In this configuration, the electric field intensity calculation unit 11 corresponds to an example of “detection unit” according to the present application, and the interface 13 corresponds to an example of “output unit” and an example of “route information acquisition unit” according to the present application. .

  Further, as shown in FIG. 3, the broadcast receiving unit 17 includes a processing unit 170, an output unit 174, a received data acquisition unit 175, a channel selection unit 176, a reception unit 177, and an antenna 178 connected to the reception unit 177. , Is configured.

  On the other hand, the server apparatus SV according to the embodiment includes an interface 1, a processing unit 4 including a CPU, a RAM, a ROM, and the like, a non-volatile HDD, a volatile memory, and the like, and a map database (FIG. 2 and below). In this description, it is abbreviated as “map DB”.) The recording unit 5 records 50 in a non-volatile manner, the operation unit 6 including a keyboard and a mouse, and the display 7 including a liquid crystal display. The interface 1 corresponds to an example of the acquisition unit 1 according to the embodiment and an example of the “second acquisition unit” according to the present application.

  The processing unit 4 includes a search unit 2 and a map DB update unit 3. At this time, the search unit 2 and the map DB update unit 3 may be realized by a so-called hardware logic circuit constituting the processing unit 4, or a route search program according to the present application to be described later for the server device SV. May be realized by software by the CPU of the processing unit 4 reading and executing the above. The search unit 2 corresponds to an example of the search unit 2 according to the embodiment, an example of the “correction unit” according to the present application, and an example of the “calculation unit” according to the present application. Furthermore, the interface 1 and the search unit 2 constitute an example of the route search device S according to the embodiment.

  In the above configuration, the interface 13 of the navigation device NV controls the exchange of data by wireless communication with the server device SV via the network NW under the control of the processing unit 10. On the other hand, the sensor unit 14 includes various autonomous sensors (for example, an acceleration sensor, an angular velocity sensor, etc.) for guiding a vehicle on which the navigation device NV is mounted, and the detection results of the various sensors are sent to the processing unit 10. Output. The GPS receiving unit 15 receives navigation radio waves (radio waves from navigation satellites included in a so-called GPS system) for detecting the current position of the vehicle, and outputs the reception results to the processing unit 10. Further, the FM broadcast receiving unit 16 receives radio waves of FM broadcasts that carry radio broadcasts of FM broadcast stations selected / designated by the operation unit 19 and so-called VICS (Vehicle Information Communication System (registered trademark)) information, The reception result is output to the processing unit 10. On the other hand, the broadcast receiving unit 17 receives a broadcast radio wave such as terrestrial digital broadcast, and outputs the reception result to the processing unit 10. At this time, the channel selection unit 176 of the broadcast reception unit 17 sets the frequency of the broadcast station selected / designated by the operation unit 19 in the reception unit 177, and receives the broadcast radio wave of the broadcast station. Thereby, the reception data acquisition unit 175 acquires the reception data corresponding to the received broadcast radio wave via the reception unit 177 and outputs it to the processing unit 170. Then, the reception level determination unit 173 of the processing unit 170 detects / determines the electric field strength of the radio wave of the broadcasting station and its connection stability, which will be described later, based on the received data, and the determination results via the output unit 174 Is output to the processing unit 10. In the following description, the electric field strength and the connection stability are collectively referred to as “electric field strength etc.” as appropriate. In parallel with this, the image data analysis unit 171 and the audio data analysis unit 172 of the processing unit 170 analyze the contents of each of the image data and the audio data included in the acquired reception data, and those contents are output via the output unit 174. The analysis result is output to the processing unit 10. As a result, the processing unit 10 outputs the image and sound included in the broadcast radio wave received by the broadcast receiving unit 17 through the display 18 of the navigation device NV and the speaker (not shown) as a result of receiving the terrestrial digital broadcast or the like. .

  Further, in the operation unit 19, various instruction operations (including the above-mentioned channel selection operation and instruction operations indicating the starting point, the destination, the point to be routed, etc. in the route search according to the embodiment) are performed on the navigation device NV. The operation unit 18 outputs an operation signal corresponding to the instruction operation to the processing unit 10. The data indicating the departure point, the destination, the point to be routed, and the like are transmitted to the server device SV via the network NW. The display 18 displays a map, route information, etc. for guidance by the navigation device NV.

  On the other hand, the electric field strength calculation unit 11 of the processing unit 10 includes, for example, the electric field strength at the time of wireless communication by the interface 13 when the navigation device NV is used (including when used for purposes other than the route search). In addition, the electric field strength and the like related to the broadcast reception by the FM broadcast receiving unit 16 and the broadcast receiving unit 17 are measured based on the outputs from the interface 13 and the FM broadcast receiving unit 16 and the broadcast receiving unit 17, respectively. Then, the electric field strength data and the connection stability data corresponding to the measurement result are output to the server device SV. In the following description, the electric field strength data and the connection stability data are collectively referred to as “electrolytic strength data etc.” as appropriate. At this time, as the output from the broadcast receiving unit 17, data indicating the electric field strength determined by the reception level determining unit 173 is used. The current position detection unit 12 of the processing unit 10 is current position data that is latitude / longitude data indicating the current position of the vehicle on which the navigation device NV is mounted, based on outputs from the GPS receiving unit 15 and the sensor unit 14. Is output to the server apparatus SV via the interface 13. The other processing unit 10 performs overall control of processing as the navigation device NV including route search processing according to the embodiment.

  On the other hand, the interface 1 of the server device SV controls the wireless communication with each navigation device NV via the network NW and the exchange of data via the network NW under the control of the processing unit 4. The operation unit 6 performs an instruction operation on the server device SV, and the operation unit 6 outputs an operation signal corresponding to the instruction operation to the processing unit 4. The display 7 displays information indicating the operation as the server device SV.

  Furthermore, as map DB50 currently recorded on the recording part 5, the map data, audio | voice data, etc. which are required for the said guidance including the route search process which concerns on the Example mentioned later are recorded on non-volatility. At this time, in the map data, for example, node data that is latitude / longitude data indicating the geographical position of a node corresponding to an intersection, a parking lot, etc., and the geographical position and shape of a road between intersections, for example, are shown. Link data is included as road data used for route search processing according to an embodiment described later. Further, the map data includes the electric field strength map according to the embodiment, showing the electric field strength of the radio wave in the position or area included in the map for each position. The electric field strength in this case is the electric field strength or the like indicated by the electric field strength data measured and transmitted by the electric field strength calculation unit 11 of each navigation device NV. In addition, the electric field strength map includes a measured value actual measurement area in which the electric field strength and the like are measured by actual measurement by the broadcast receiving unit 17 of each navigation device NV, and an electric field in the area based on the electric field strength and the like measured by the actual measurement. And a measured value estimation area where strength and the like are “estimated”.

  Then, the map DB update unit 3 of the processing unit 4 converts the electric field strength map in the map DB 50 based on the electric field strength data transmitted from each navigation device NV by the electric field strength map generation processing described later. Update. At this time, the map DB update unit 3 updates the field strength data and the like related to the measured value actual measurement area by the actual measurement, and also relates to the measured value estimation area based on the field strength data and the like related to the measured value actual measurement area. Estimate / update field strength data. The electric field strength map according to the embodiment will be described later with reference to FIG.

  As a result, when the search unit 2 of the processing unit 4 receives data indicating the departure point, the destination, and the point to be routed from any of the navigation devices NV, the search unit 2 includes the departure point and the destination. The route of the vehicle according to the embodiment is searched. And the search part 2 transmits the search data as the said search result with respect to the navigation apparatus NV which transmitted the data which show the said departure place etc. via the said network NW. At this time, when searching for the route, the search unit 2 determines that a point or road on the map whose field strength is relatively weak is based on the field strength map included in the map DB 50. The search for a route to a desired destination is advanced while selecting a search candidate so that it is less likely to be included in a route as a search result than a relatively strong point or road.

  As a result, the processing unit 10 of the navigation device NV that has transmitted the data indicating the departure place and the like displays the route as the search result transmitted from the server device SV on, for example, the display 18 to display the user. (That is, it is used for setting of a guidance method by a driver or a passenger).

  Next, the route search processing according to the embodiment will be specifically described with reference to FIGS. The route search process described below is executed centering on the processing unit 10 of any one of the navigation devices NV and the processing unit 4 of the server device SV shown in FIG. In addition, the route search processing is compared with the conventional route search processing by the so-called Dijkstra method using the node data and the link data in the road data included in the map DB 50 recorded in the recording unit 5 of the server SV. In addition, search candidate selection processing using the electric field strength map according to the embodiment is added.

  More specifically, the route search process according to the embodiment is a route search process by a conventional so-called Dijkstra method based on the data indicating the departure place specified in any of the navigation devices NV for which the route search is desired. On the other hand, the electric field intensity indicated by the electric field intensity map (the electric field intensity map recorded in the map DB 50 of the recording unit 5) generated / updated by the process described with reference to FIGS. The calculation process of the integrated cost mentioned later based on strength is added. Here, the “accumulated cost” is data for each link or node indicating whether or not the link or node included in the map data is easily selected as the final route. At this time, the higher the integrated cost is, the more difficult it is to be selected as the route, and as the final route, a route in which links or nodes having the lowest integrated cost is selected is selected.

(I) Process of Generating and Updating Field Strength Map First, the process of generating and updating the field intensity map according to the embodiment will be specifically described with reference to FIGS.

  As described above, the electric field strength map according to the embodiment indicates the electric field strength indicating the electric field strength of the radio wave in the position or area included in the map corresponding to the map data included in the map DB 50 for each position. It is a map. The radio waves in this case include radio waves for wireless communication by the interface 13 in each navigation device NV via the network NW, radio waves for FM broadcast received by the FM broadcast receiving unit 16 in each navigation device NV, and in each navigation device NV. Three types of radio waves are included: broadcast radio waves received by the broadcast receiving unit 17. The electric field intensity map shows the measured value actual measurement area and the measurement value estimation area described above.

  First, the electric field strength measurement process according to the embodiment will be described with reference to FIG. The electric field strength measurement process shown in FIG. 4 is mainly executed by the electric field strength calculator 11 of each navigation device NV.

  That is, as shown in FIG. 4, as the electric field intensity measurement processing according to the embodiment, the electric field intensity calculation unit 11 first measures the electric field intensity I measured based on the outputs from the interface 13, the FM broadcast receiving unit 16, and the broadcast receiving unit 17. Current position data (latitude / longitude data) from the current position detector 11 indicating the position where the electric field intensity I is measured, time data from a timer (not shown) indicating the time t when the electric field intensity I is measured, and an interface Four pieces of time data indicating the time when the connection by wireless communication in 13 or the like has been established (hereinafter, this time is referred to as “connection establishment time”) are acquired from the broadcast receiving unit 17 or the like (step S100). . At this time, the electric field intensity I is data obtained by standardizing the electric field intensity value detected by the broadcast receiving unit 17 or the like in a range of “0.0” to “1.0”. The connection establishment time includes the network connection establishment time during which the connection between the interface 13 and the network NW has been established, the broadcast reception time during which the FM broadcast can be normally received by the FM broadcast receiving unit 16, and the broadcast This is a time calculated based on one of three reception times during which the receiving unit 17 was able to normally receive terrestrial digital broadcasting or the like. More specifically, as the connection establishment time, for example, the longest time among the three times may be adopted as the connection establishment time related to the processing of step S100, or the ease of acquiring traffic jam information is preferentially handled. May adopt the reception time of the FM broadcast carrying the VICS information as the connection establishment time related to the processing of step S100, or the broadcast receiving unit 17 when handling the ease of receiving the terrestrial digital broadcast preferentially. The broadcast reception time may be adopted as the connection establishment time for the process of step S100.

  If the electric field intensity I and the like can be acquired in the process of step S100, the electric field intensity calculation unit 11 next uses the link (the map data recorded in the recording unit (not shown) of the navigation device NV) that the vehicle has passed immediately before. The connection stability s of radio waves in the link that the vehicle has passed immediately before is calculated (step S101). This connection stability s is defined by the following equation.

Connection stability s = connection establishment time during passage through the previous link / time required for passage through the link At this time, the electric field strength calculation unit 11 determines the connection establishment time during passage through the previous link from the broadcast reception unit 17 and the like. get. The time required for the passage of the link can be acquired as the vehicle moves based on the current position data from the current position detector 12.

  Next, the electric field strength calculating unit 11 determines whether (wireless) communication by the interface 13, the FM broadcast receiving unit 16 or the broadcast receiving unit 17 is currently established (step S102). In the determination in step S102, when the communication is currently established (step S102; YES), the electric field strength calculation unit 11 proceeds to the process in step S104 described later. On the other hand, in the determination of step S102, when the communication is not currently established (step S102; NO), the electric field strength calculation unit 11 uses the electrolytic strength I measured in the previous electrolytic strength measurement process shown in FIG. The measurement result of intensity I is recorded (accumulated) in a recording unit (not shown) of the navigation device NV (step S103). Thereafter, the electric field strength measuring unit 11 determines whether or not the current position has reached the next link due to the movement of the vehicle on which the navigation device NV is mounted (step S104). If it is determined in step S104 that the current position has not yet reached the next link (step S104; NO), the above steps S100 to S104 are repeated in order to repeat the process in steps S100 to S104 for the link including the current position of the vehicle. The process returns to S100. On the other hand, if it is determined in step S104 that the current position of the vehicle is on the next link (step S104; YES), the electric field intensity calculation unit 11 determines the electric field intensity I for the link including the current position until immediately before. Then, the field strength data indicating the connection stability s is transmitted to the server device SV via the network NW (step S105). Thereafter, the electric field intensity calculation unit 11 ends the measurement of the electric field intensity or the like when, for example, the vehicle on which the navigation device NV is mounted arrives at the destination or the navigation device NV is turned off. It is determined whether or not (step S106). In the determination in step S106, when the measurement of the electric field strength or the like is finished (step S106; YES), the electric field strength calculation unit 11 finishes the measurement, while when the measurement is continued (step S106; NO), the electric field strength. The calculation unit 11 returns to the process of step S100 and continues measurement of the electric field strength and the like. When the vehicle passes through an area (link) where radio communication with the network NW, radio wave reception unit 16 and broadcast reception unit 17 cannot receive all radio waves, the electric field strength calculation unit 11 A flag indicating that “communication is not possible” is set and transmitted to the server device SV as the electric field strength data.

  Next, the electric field intensity distribution data generation processing according to the embodiment will be described with reference to FIG. The field strength distribution data generation processing shown in FIG. 5 is mainly executed by the map DB update unit 3 of the server device SV that has received the field strength data and the like from each navigation device NV.

  That is, as shown in FIG. 5, as the field strength distribution data generation processing according to the embodiment, the map DB update unit 3 firstly stores the current map DB 50 in the current map DB 50 for an area including a link in which the flag indicating that communication is not possible is set. It is determined whether or not field strength data or the like is stored as a field strength map (step S110). If it is determined in step S110 that the region does not store field strength data or the like as a field strength map (step S110; NO), the map DB update unit 3 determines the first measurement point k0 and current time t0 in the region. Then, the field strength degree data including the field strength I0 is received from any of the navigation devices NV (step S111). Next, the map DB update unit 3 generates an electric field intensity map for the measurement point k0 using the electric field intensity data received by the process of step S111 (step S112). The electric field intensity map generation processing in step S112 will be described in detail later with reference to FIGS. Next, the map DB update unit 3 determines whether or not the area is an unmeasured area such as an electric field intensity (step S113). If it is determined in step S113 that the area is an unmeasured area (step S113; YES), the map DB update unit 3 uses the field strength data measured in the measured value actual area and the unmeasured area. The field strength data and the like for the unmeasured area are updated by estimating the field strength data and the like (step S114). At this time, the electric field strength data and the like of the unmeasured area are updated as the measured value estimation area. Thereby, map DB update part 3 ends electric field strength distribution data generation processing concerning an example. The update processing of the electric field strength data and the like for the unmeasured area in step S114 will be described in detail later with reference to FIGS.

  On the other hand, if it is determined in step S110 that the region is where the field strength data is stored as the field strength map (step S110; YES), the map DB update unit 3 measures each measurement point k0 to measurement in the region. The electrolytic strength data including the current time t0 to the current time tL-1 and the electric field strength I0 to the electric field strength IL-1 for the starting point kL-1 are sequentially received from any navigation device NV (step S115). Here, “L” is a parameter that is a natural number and indicates the number of electric field strength data and the like accumulated in the map DB at that time. Next, the map DB update unit 3 generates a field strength map for each measurement point k0 to measurement point kL-1 using each field strength data received by the process of step S115 (step S116). ). The electric field intensity map generation process in step S116 will be described later in detail with reference to FIGS. 6 and 7 as in the electric field intensity map generation process in step S112. Next, the map DB update unit 3 determines whether or not the generation process of the electric field intensity map has been completed for all measurement points k in the area (step S117), and if not completed (step S117; NO) ) The map DB update unit 3 performs the process of step S116 for the measurement point k that has not been completed. On the other hand, if it is determined in step S117 that the field intensity map generation processing has been completed for all measurement points k in the area (step S117; YES), the map DB update unit 3 proceeds to the determination in step S113. Thereafter, the process of step S114 is executed.

  Next, the electric field intensity map generation processing in steps S112 and S116 will be specifically described with reference to FIGS. In addition, since the process is basically the same between the case where the electric field intensity map is generated using the electric field intensity I and the case where the electric field intensity map is generated using the connection stability s, FIG. In the description using FIG. 7, the electric field intensity map generation processing using the electric field intensity I will be described on behalf of these.

  As shown in FIG. 6, as the electric field intensity map generation processing in steps S112 and S116, time data indicating the current time t for any measurement point k by the processing in step S111 or the processing in step S115 immediately before each. When the field strength data including the field strength I is acquired (step S120), the map DB update unit 3 firstly selects a time zone t to which the acquired current time t belongs among a plurality of preset time zones. (H) ≦ t <t (h + 1), intensity band I (j) ≦ I <I (j + 1) to which the electric field intensity I belongs among a plurality of preset intensity bands, and the measurement point k belongs Mesh coordinates (mesh units) (xi, yi) are respectively calculated (step S121). Here, the “mesh coordinates” according to step S121 is a mesh-like coordinate system set on a work area (not shown) of the recording unit 5 (corresponding to a map but separate from the map coordinates). ). Thereafter, the map DB update unit 3 preliminarily calculates the average value, variance, etc. of the electric field strength, the connection establishment time, and the electric field strength data related to the measured value measurement area in the vicinity at the mesh coordinates (xi, yi) at the current time ti. The set statistical data is updated (step S122). Thereafter, the map DB update unit 3 determines that all the mesh coordinates are hierarchical mesh coordinates such that one mesh element (mesh unit) in the upper hierarchy is formed by a plurality of mesh units in the lower hierarchy, for example. The update processing according to step S122 is performed on the mesh coordinates of the layer (step S123). Next, the map DB update unit 3 determines whether or not the flag indicating that communication is not possible is set for the link including a certain measurement point k at the current time t (step S124), and the flag is not set. In this case (step S124; NO), the process proceeds to the determination in step S113 or the determination in step S117. On the other hand, if it is determined in step S124 that the communication impossibility flag is set (step S124; YES), the map DB update unit 3 next sets the average electric field strength for the mesh element including the measurement point k in advance. It is determined whether or not it is equal to or less than the threshold value (step S125). If it is determined in step S125 that the average electric field strength is less than or equal to the threshold (step S125; YES), the map DB update unit 3 sets the flag indicating that communication is not possible for the mesh coordinates (xi, yi). (Step S126), and then the process proceeds to the determination in Step S113 or the determination in Step S117. On the other hand, if the average electric field strength is not less than or equal to the threshold value in the determination in step S125 (step S125; NO), the map DB update unit 3 directly proceeds to the determination in step S113 or the determination in step S117.

  When the electric field strength map generation process shown in FIG. 6 is performed, the map DB 50 illustrates the electric field strength I, for example, in FIG. 7A, and the connection stability s, for example, in FIG. 7B. As described above, for each mesh coordinate (xi, yi), a map such as an electric field intensity indicating the electric field intensity I or the connection stability s is generated for each different current time t. In FIG. 7, the darker the hatching color, the stronger the electric field intensity I or the more stable the connection stability s.

  Next, the measurement value estimation area update process in step S114 will be specifically described with reference to FIGS. In the update process of the measured value estimation area in step S114, the electric field strength of the area where the electric field strength is not measured is estimated using the so-called curved surface fitting method according to the embodiment. The curved surface fitting method itself is generally a known technique.

  That is, as an update process of the measured value estimation area in step S114, when the target area is an unmeasured area in the determination in step S113 immediately before (step S113 in FIG. 5; see YES), the previous area After acquiring the time data indicating the current time t and the electric field intensity data including the electric field intensity I for any of the measurement points k acquired by the process of step S112 or the process of step S115 (step S130), update the map DB First, similarly to step S21 shown in FIG. 6, the unit 3 is preset in a time zone t (h) ≦ t <t (h + 1) to which the acquired current time t belongs among a plurality of predetermined time zones. Among the plurality of intensity bands, the intensity band I (j) ≦ I <I (j + 1) to which the electric field intensity I belongs, and the mesh coordinates to which the measurement point k belongs Respectively calculated (step S131).

  Next, the map DB update unit 3 acquires the measured field strength data and the like in the mesh coordinates (xi, yi) in a certain time zone t (h) ≦ t <t (h + 1) from any of the navigation devices NV ( Step S132). Here, the distribution of the mesh coordinates (in other words, the measured value actual measurement area according to the embodiment) from which the measured field strength data and the like have been acquired by the process of step S132 is, for example, FIG. 9A and FIG. ) And the area distribution indicated by hatching in FIG. 10.

  Next, the map DB update unit 3 performs so-called “closing processing” a plurality of times on each mesh coordinate (see FIG. 9A) for which the field strength data has been acquired, so that each measured measurement area (mesh coordinate) is obtained. They are connected (step S133) and further subjected to a so-called “opening process” once to remove noise (step S134). As a result of the processing in step S133 and the processing in step S134, for example, as illustrated in FIG. 9B, the above measured value actual measurement regions may be divided into a plurality of regions (measurement value estimation regions (checks in FIG. 9B and FIG. 10). Are connected by pattern hatching))).

  Next, the map DB update unit 3 determines an area to be subjected to the curved surface fitting method by so-called dilation processing (step S135), and further identifies and updates a cluster in which measured value measurement areas are continuous by so-called labeling processing. (Step S136). It is assumed that, for example, the clusters K1 to K7 illustrated in FIG. 10 have been identified / updated by the processing up to step S136. In this case, each cluster K is a cluster in which a plurality of measured value measured areas are connected by one or a plurality of measured value estimated areas (in other words, a plurality of measured value measured areas are filled with one or a plurality of measured value estimated areas). It becomes.

  Thereafter, the map DB update unit 3 identifies the cluster K to which a certain mesh coordinate (xi, yi) belongs (step S137), and further in the mesh coordinate (xi, yi) in the time zone t (h) ≦ t <(h + 1). The average value of the electric field intensity I and the average value of the connection stability s are respectively acquired (step S138). Finally, the map DB update unit 3 performs a process of updating the parameter α as the curved surface fitting method. In other words, the map DB update unit 3 performs a curved surface fitting method on a certain cluster K and updates the parameter αK (step S139). Thereafter, the map DB update unit 3 ends the electric field intensity distribution data generation process according to the embodiment.

  Here, the curved surface fitting method means that the electric field intensity zi at a certain time at a measurement point k where the mesh coordinates at a certain time is (xi, yi) is represented by zi = I (xi, yi) (i is a measured value actual measurement area). This is a process for calculating the parameter α = (a0, a1,..., AN) as M). Here, “N” is a natural number and is a constant set in advance in order to efficiently perform the curved surface fitting method according to the embodiment used for estimating the electric field strength data and the like. In the curved surface fitting method using a quadric surface as an example, the cost function CT is calculated by the following formula (1) (for example, when the value of N is defined as “5” as an example), and the cost-related CT is the smallest. Is calculated using a so-called fastest descent method. At this time, the second term including the positive number λ in the following equation (1) is a regularization term for reducing overlearning. Further, in this case, “overlearning” generally means a state in which there is little error with respect to an already given measurement value, but on the contrary, an error becomes large for a measurement value to be given.

Then, the parameter α is updated by the following equation (2-1) under the above conditions by the fastest descent method. The following formula (2-2) will be described later.

At this time, γ is a parameter for determining the descending speed. Note that the descent speed may be adjusted by monotonically decreasing the value of γ according to the number of trials.

  Here, in the curved surface fitting method using the fastest descent method according to the embodiment, a plurality of measurement results are divided into so-called “teacher data” and so-called “test data”, and the so-called cross-validation method is used to reduce the verification error. For example, the maximum number of measured values (M above), the number of fitting parameters (N above), the coefficient λ of regularization terms, and the descent speed γ are set in advance, for example, and the influence of generalization error and over-learning Calculate a small set of parameters. Here, the above-mentioned “generalization error” is generally a scale indicating how much the formula (1) and the parameter α can be configured for a given measurement value. In the curved surface fitting method according to the embodiment, it is required to reduce both the generalization error (in other words, improve the generalization ability) and prevent the overlearning.

  In addition, as a method specifically used as the cross-validation method, for example, a known k-division cross-validation method and the like can be cited. Further, for example, the influence can be reduced by increasing the number N of fitting parameters in order to determine a parameter with higher generalization ability, and increasing the regularization term λ in the case of overlearning.

  Furthermore, when the number of measured values is large, it takes a very long time to update the parameter α, so a so-called online learning method (sequential learning method) may be used. In this case, every time a new measurement value is received, the fitting parameter α is set using a method (so-called stochastic gradient method) that uses the above equation (2-2) instead of the above equation (2-1). What is necessary is just to update sequentially. If this online learning method is used, the calculation process can be completed only once each time the measurement value is updated, and the overall processing load can be reduced. These matters are described in, for example, “Pattern Recognition and Machine Learning (Part 1) Statistical Prediction by Bayesian Theory, CM Bishop, Hiroshi Motoda, Takio Kurita, Tomoyuki Higuchi, Yuji Matsumoto, Noboru Murata, 2007/12 Detailed on "Month" etc.

(II) Route Search Processing Next, according to the embodiment using the field strength map according to the embodiment which is constantly updated by the processing such as generation and update of the field strength map described with reference to FIGS. The search process will be described with reference to FIGS.

  In the route search processing according to the embodiment, for example, in the navigation device NV, an operation to search for a route to the destination is set by the user setting the destination of movement of the vehicle on which the vehicle is mounted. The fact that it is executed in the operation unit 19 together with the input operation of data indicating the ground or the like is started at the timing when it is transmitted to the server apparatus SV via the network NW. As a route search process according to the embodiment, the search unit 2 of the server device SV first performs a process of adding a link closest to the search start point to the search candidate as shown in FIG. 11 (step S1). Specifically, as the processing of step S1, the search unit 2 obtains node data indicating a node connected to the link closest to the search start point based on the link data and the node data in the map data recorded in the recording unit 5. By recording the search candidate in a memory (not shown) in the search unit 2, the node is added to the search candidate. Here, in many cases, the search start point is a position corresponding to the departure point or the current position of the vehicle.

  Next, the search unit 2 has a node as a search candidate remaining in its own memory (not shown), or the determined shortest route has reached the destination, and the navigation device NV for which the route search is desired is It is determined whether or not a message has been transmitted (that is, whether or not the area where the shortest route has been determined by sequentially searching from the starting point has spread and has reached the destination) (step S2). . Of the determinations in step S2, whether or not a node as a search candidate remains is determined by checking whether or not node data indicating the node as the search candidate is recorded in the memory (not shown). Is done. In the determination in step S2, if there is no remaining node as a search candidate or the shortest route has reached the destination (step S2; NO), the processing unit 4 including the search unit 2 is in the embodiment. The route search process is finished.

  On the other hand, if it is determined in step S2 that nodes as search candidates remain and the shortest route has not yet reached the destination (step S2; YES), the search unit 2 is set next. The link with the minimum accumulated cost accumulated along the search condition is selected (step S3). In FIG. 11 and the following description, the link having the minimum accumulated cost is indicated as “link L_min”. A node on the start point side of the link L_min is referred to as a node M_min, and a node on the end point side is referred to as a node N_min. Next, the search unit 2 determines whether or not the link L_min selected by the process of step S3 is applicable to a predetermined exclusion condition, and if the exception is satisfied, excludes the link L_min from the search candidate. Exclusion determination is performed (step S4). Examples of the exclusion condition in step S4 include a condition that the road corresponding to the link L_min is closed due to time restrictions, or a condition that the road cannot pass due to one-way restrictions.

  Next, the search unit 2 repeats the following processing for all the links L_j (j is a link number; hereinafter the same) connected to the link L_min.

First, the search unit 2 calculates the passage cost c (L_j) of the link L_j using the electric field strength map according to the embodiment (step S5). The process in step S5 will be described in detail later with reference to FIG. Next, the search unit 2 calculates / acquires an integrated cost C (L_min) from the departure point of the vehicle on which the navigation device NV is mounted to the current link L_min (step S6). Next, the search unit 2 calculates the accumulated cost C ′ to the node N_j on the end point side connected to the current link L_j,
C ′ = c (L_j) + C (L_min)
(Step S7). Then, the search unit 2 determines whether there is another path connected to the current node N_j (step S8). In FIG. 11 and the following description, the other route is referred to as a route P ′. If it is determined in step S8 that there is no other route P ′ (step S8; NO), the search unit 2 sets the accumulated cost C (N_j) for the current node N_j to the accumulated cost C ′ (step S8). S10).

  On the other hand, if it is determined in step S8 that there is another route P ′ (step S8; YES), the search unit 2 next determines that the accumulated cost to the node N_j of the other route P ′ is Cp ′. Then, it is determined whether or not the accumulated cost Cp ′ is larger than the accumulated cost C ′ when the current link L_j is routed (step S9). When the accumulated cost Cp ′ is larger than the accumulated cost C ′ in the determination in step S9 (step S9; YES), the search unit 2 proceeds to the process in step S10. On the other hand, when it is determined in step S9 that the accumulated cost Cp ′ is not greater than the accumulated cost C ′ (step S9; NO), the search unit 2 next performs step S5 for all the links L_j connected to the link L_min. It is determined whether the process or the process of step S10 has been completed (step S11). If it is determined in step S11 that there is a link L_j for which the process from step S5 to step S10 has not been completed among all the links L_j connected to the link L_min (step S11; NO), the remaining link L_j In order to repeat the process from step S5 to step S10, the process proceeds to step S5. On the other hand, if it is determined in step S11 that the processing from step S5 to step S10 has been completed for all links L_j connected to the link L_min (step S11; YES), the search unit 2 determines that the current link L_min Is completed, and the link data is deleted from the recording unit 5 so as to exclude the link L_min from the search candidates (step S12). Thereafter, the search unit proceeds to the process of step S2 to repeat the process of step S2 to the process of step S12 for the next search candidate.

  Next, the calculation process of the passage cost c (L_j) using the electric field intensity map according to the embodiment of step S5 will be described more specifically with reference to FIG.

  As shown in FIG. 12A, in calculating the passage cost c (L_j), the search unit 2 firstly sets a time zone t (h) ≦ t to which the current time t belongs among a plurality of preset time zones. <T (h + 1) and mesh coordinates (xi, yi) to which the current link L_j (measurement point k) belongs are calculated (step S50).

  Next, the search unit 2 has already measured the electric field intensity I of the mesh coordinates (xi, yi) at the time ti (in other words, the mesh coordinates (xi, yi) is the measured value actual measurement area in the electric field intensity map according to the embodiment. Whether it can be calculated as a theoretical value (step S51). Specifically, as the determination in step S51, for example, the position of a so-called base station for connecting the interface 13 of the navigation device NV to the network NW and the output value of the radio wave therefrom are known in advance. If it is possible to calculate the theoretical value of the electric field intensity I within the reach of the radio wave, it is determined that the theoretical value can be calculated (step S51; YES).

  When the determination result of step S51 is “NO”, the search unit 2 sets the cost value c0 (L_j) of the link L_j by the same method as the conventional method as the passage cost c (L_j) of the link L_j (step S59). Thereafter, the process proceeds to step S6 in FIG.

  On the other hand, when the determination result in step S51 is “YES”, the search unit 2 next determines that the mesh coordinates (xi, yi) at the target time ti is the measured value actual measurement area in the electric field strength map according to the embodiment. It is determined whether it belongs to any of the above (step S52). In the determination of step S52, when the mesh coordinates (xi, yi) at the time ti belong to any of the measured value actual measurement regions (step S52; YES), the search unit 2 uses the electric field strength map according to the embodiment. Electric field strength data and connection stability data of mesh coordinates (xi, yi) at time ti are acquired (step S59-1). Thereafter, the search unit 2 proceeds to the process of step S56 described later.

  On the other hand, if it is determined in step S52 that the mesh coordinates (xi, yi) at the time ti do not belong to any of the measured value actual measurement areas (step S52; NO), the search unit 2 next selects the mesh coordinates at the time ti. It is determined whether (xi, yi) belongs to one of the measurement value estimation regions in the electric field intensity map according to the embodiment (step S53). If it is determined in step S53 that the mesh coordinates (xi, yi) at time ti do not belong to any of the measurement value estimation regions (step S53; NO), the search unit 2 proceeds to the process of step S59. On the other hand, if it is determined in step S53 that the mesh coordinates (xi, yi) at the time ti belong to any of the measurement value estimation regions (step S53; YES), the search unit 2 uses the mesh coordinates (xi, yi). ) To which the cluster K (see FIG. 10) belongs is acquired from the map DB 50 (step S54). Then, the search unit 2 acquires the parameter α for the curved surface fitting method corresponding to the acquired cluster K, thereby obtaining the estimated value zi of the electric field intensity I at the mesh coordinates (xi, yi) by the following formula (3 ) (Step S55).

Estimated value I
= Zi above
= A0 + a1 × xi + a2 × yi + a3 × xi ² + a4 × xi × yi + a5 × yi ²
(3)
Next, the search part 2 determines whether the flag which shows that communication is impossible is set about the area | region corresponding to the mesh coordinate (xi, yi) (step S56). In the determination of step S56, when the flag indicating that communication is not possible is not set (step S56; NO), the search unit 2 sets the passage cost of the link L_j in the same route search processing as the conventional as c0 (L_j) The passage cost c (L_j) of the link L_j according to the embodiment is calculated by the following equation (4) (step S58).

c (L_j) = (1 + constant A * (1-I) + constant B * (1-s)) * c0 (L_j)
(4)
Here, the constant A is a preset parameter for adjusting the difficulty in adopting a region where the electric field intensity I is weak as a search result. The constant B is also a preset parameter for adjusting the difficulty in adopting an area where the connection stability s is low as a search result. Thereafter, the search unit 2 proceeds to the process of step S6 in FIG.

  On the other hand, when the flag indicating that communication is not possible is set in the determination in step S56 (step S56; YES), the search unit 2 uses the field strength data for the area corresponding to the mesh coordinates (xi, yi). Are initialized ("0") (step S57), and then the process proceeds to step S58.

  The route search process using the electric field strength maps according to the embodiments shown in FIGS. 11 and 12A described above is executed, for example, as shown in a schematic map in FIG. If there are a plurality of roads R between the place ST and the destination OB, and there is a low electric field strength region LI and a low connection stability region LS on the way, the constant A> 0 and the constant B = 0. In the case of setting in advance (that is, when only the electric field intensity I is considered in the calculation of the passage cost), the route RT1 in FIG. 12B is the final when compared with the route RT3 illustrated in FIG. It becomes difficult to be selected as a general route. Here, the route RT3 has a passage cost equivalent to that when the constant A = 0 and the constant B = 0 (that is, the calculation of the passage cost c (L_j) does not consider the electric field strength and the connection stability). It is an example of the path | route used as c (L_j). On the other hand, when the constant A = 0 and the constant B> 0 is set in advance (that is, when only the connection stability s is considered in the calculation of the passage cost), the route RT2 in FIG. It is difficult to select the final route as compared to the route RT3. Furthermore, when the constant A> 0 and the constant B> 0 are set in advance (that is, when both the electric field strength I and the connection stability s are taken into account in the calculation of the passage cost), the path in FIG. RT1 or route RT2 is less likely to be selected as the final route than route RT3, and although not shown in FIG. 12B, passes through both the low electric field strength region LI and the canonical stability region LS. The route is more difficult to be selected as the final route than the route RT3.

  As described above, according to the route search processing according to the embodiment, based on the electric field strength of each region, the link in the region where the electric field strength is low is less likely to be searched than the link in the other region. To search for a route. Therefore, for example, when it is desired to move by selecting an area where the reception situation of the radio wave for data acquisition is good, it is possible to automatically and appropriately select an area where the reception situation is better and search for a desired route.

  Further, the passage cost c (L_j) for each link or the like is corrected based on the electric field strength or the like, and whether or not a link or the like in an area where the electric field strength or the like is low is searched as a part of the route is corrected. A route is searched by making a decision based on the cost c (L_j). Therefore, since the passage cost c (L_j) for each link or the like is corrected based on the electric field strength or the like and used for the route search, a route with good reception conditions can be searched accurately and effectively.

  Furthermore, since the route is searched using the electric field strength map including the measured value measurement area and the measured value estimation area, even if there is a link in an area where the radio wave reception status is not actually measured, the unmeasured reception status It is possible to accurately and effectively search for a route with good reception conditions while appropriately supplementing.

  Furthermore, since the reception situation in the area adjacent to the measurement value measurement area and where the reception situation is not actually measured is estimated based on the electric field strength obtained by the actual measurement of the reception situation, there is an area where the reception situation cannot be actually measured. Even in this case, the reception status can be estimated and used for route search. The “adjacent” in this case is when the measured value measurement area and the measurement value estimation area are in contact with each other, when some of them overlap each other, or when they are separated but adjacent to each other. Three cases are included.

  In addition, the field strength data is associated with the time or time based on the current time data, and the route is further searched based on the time or time. Therefore, the route with good reception status is reflected while reflecting the reception status that changes every moment. Can be searched accurately and effectively.

  Further, based on at least one of the electric field intensity I for each region or the connection stability S for each region, the route is set such that a link having a low electric field mirror etc. is less likely to be searched than a link in another region. Explore. Therefore, a desired route can be searched by automatically and appropriately selecting a region where the reception status of the radio wave or the stability of the connection via the radio wave is better.

  In the process of step S58 of the embodiment described above, when the link L_j extends over a plurality of meshes, all mesh coordinates through which the target link L_j passes are specified, and those mesh elements are also specified. , Li is the length that each link L_j passes through, and the electric field intensity at time ti, mesh coordinates (xi, yi), and the like are acquired from the electric field intensity map in the map DB 50. Then, in the same route search processing as the conventional one, the length of the link L_j is L (L_j), the passage cost is c0 (L_j), and the passage cost c (L_j) of the link L_j according to the embodiment is expressed by the following equation (5). It may be calculated by the following.

In equation (5), the definitions of constant A and constant B are the same as in equation (3) above.

  Further, in the calculation process of the passage cost c (L_j) described with reference to FIG. 12, when the mesh coordinates are composed of a plurality of layers as described above, the passage cost c (L_j) is determined for each layer. Can also be configured to calculate.

  In the embodiment described above, the route search process according to the embodiment is configured to be executed centering on the server device SV using data from each navigation device NV. However, the route search according to the embodiment is also provided. The processing itself may be configured to be executed in each navigation device NV. In this case, it is necessary to configure each navigation device NV to include the recording unit 5 (including the map DB 50) according to the embodiment and to be able to acquire electric field strength data and the like from other navigation devices NV in each navigation device NV. There is.

  Furthermore, although the Example mentioned above demonstrated the case where the route search process which concerns on embodiment was applied with respect to the route search process for the navigation apparatus NV mounted in the vehicle, in addition to this, for example, a person possesses When performing route search processing as part of guidance processing in a system including a smartphone, a portable information terminal device, and a server device, it is also possible to apply the route search processing according to the embodiment.

  In addition, a route search program corresponding to the flowcharts shown in FIGS. 4 to 6, 8, 11, or 12 is recorded on a recording medium such as an optical disk or a hard disk, or via a network such as the Internet. It is also possible to cause the microcomputer or the like to function as the processing unit 4 and the processing unit 10 according to the embodiment by reading out and executing this by a general-purpose microcomputer or the like.

1 Acquisition means (interface)
2 Search means (search unit)
DESCRIPTION OF SYMBOLS 3 Map DB update part 4, 10 Processing part 5 Recording part 11 Electric field strength calculation part 12 Current position detection part 13 Interface 16 FM broadcast receiving part 17 Broadcast receiving part 50 Map DB
SS route search system SV server device NV, NV1, NV2, NV3, NV4, NVn Navigation device

Claims (11)

In a route search device for searching for a movement route on which a moving body moves and including at least one of a plurality of movement routes or movement points,
Acquisition means for acquiring reception status information indicating reception status of radio waves in the mobile body for each region;
Based on the acquired reception status information, the at least one in the poor reception area where the reception status is relatively poor with respect to another area is more than the at least one in the other area. Search means for searching for the travel route in such a way that it is difficult to be searched as part of the travel route;
A route search apparatus comprising: The route search device according to claim 1,
The search means includes a correction means for correcting a search index (cost) indicating the difficulty of being searched as a part of the travel route for each of the at least one based on the acquired reception status information. ,
The search means determines whether the at least one of the at least one in the reception deterioration area is searched as the part based on the corrected search index, and searches the moving route. A route search device. In the route search device according to claim 1 or 2,
Based on the reception status information, the reception status in the region where the reception status is not actually measured is calculated, further comprising a calculation means for generating calculated reception status information indicating the calculated reception status,
The searching means, based on the acquired reception status information and the calculated calculated reception status information, the at least one in the poor reception area is the at least one in the other area. A route search apparatus for searching for a movement route so that it is less likely to be searched as a part of the movement route than one. In the route search device according to claim 3,
Based on the reception status information obtained by actual measurement of the reception status, the calculation means calculates the reception status in the area adjacent to the area where the reception status is actually measured and where the reception status is not actually measured. A route search device that calculates and generates the calculated reception status information. In the route search device according to any one of claims 1 to 4,
The reception status information is associated with time or time,
The searching means is further based on the associated time or time, and the at least one in the poor reception area is a part of the travel route than the at least one in the other area. A route search device characterized by searching for a moving route so as not to be searched. In the route search device according to any one of claims 1 to 5,
A second acquisition means for acquiring connection stability information indicating the stability of connection with the outside via radio waves in the mobile body for each region;
The searching means is based on at least one of the acquired reception status information or the acquired connection stability information, and at least one of the travel path or the travel point in the poor reception area is A route search device, wherein a search is made for a travel route that is less likely to be searched as a part of the travel route than at least one of the travel route or the travel point in another area. In the terminal device provided in the mobile body,
Detecting means for detecting the reception status of radio waves in the mobile body for each region;
Output means for outputting to the outside reception status information indicating the detected reception status;
Route information acquisition for acquiring movement route information indicating a movement route of the mobile body including at least one of a plurality of movement routes or movement points and searched for based on the output reception status information Means,
With
The searched movement route is such that the at least one in the region where the reception status is relatively poor with respect to another region is one of the movement routes than the at least one in the other region. A terminal device characterized by being a travel route searched so as not to be searched as a part. In a route search method executed in a route search device that searches for a movement route that a moving body moves and includes at least one of a plurality of movement routes or movement points,
An acquisition step of acquiring reception status information indicating the reception status of radio waves in the mobile body for each region;
Based on the acquired reception status information, the at least one in the poor reception area where the reception status is relatively poor with respect to another area is more than the at least one in the other area. A search step of searching for the travel route in such a way that it is difficult to be searched as part of the travel route;
A route search method comprising: In an information processing method executed in a terminal device provided in a mobile body,
A detection step of detecting the reception status of radio waves in the mobile body for each region;
An output step of outputting reception status information indicating the detected reception status to the outside;
Route information acquisition for acquiring movement route information indicating a movement route of the mobile body including at least one of a plurality of movement routes or movement points and searched for based on the output reception status information Process,
Including
The searched movement route is such that the at least one in the region where the reception status is relatively poor with respect to another region is one of the movement routes than the at least one in the other region. An information processing method characterized by being a travel route searched so as not to be searched as a part. A computer that is included in a route search device that searches for a movement route on which a moving body moves and includes at least one of a plurality of movement routes or movement points,
An acquisition means for acquiring reception status information indicating the reception status of radio waves in the mobile body for each region; and
Based on the acquired reception status information, the at least one in the poor reception area where the reception status is relatively poor with respect to another area is more than the at least one in the other area. Search means for searching for the travel route in such a way that it is difficult to be searched as part of the travel route;
A route search program characterized by functioning as: A computer included in a terminal device provided in a mobile object,
Detection means for detecting the reception status of radio waves in the mobile body for each region;
Output means for outputting reception status information indicating the detected reception status to the outside; and
Route information acquisition for acquiring movement route information indicating a movement route of the mobile body including at least one of a plurality of movement routes or movement points and searched for based on the output reception status information means,
An information processing program that functions as
The searched movement route is such that the at least one in the region where the reception status is relatively poor with respect to another region is one of the movement routes than the at least one in the other region. An information processing program characterized by being a travel route searched so as not to be searched as a part.