JP2007218923A - Method for searching route in navigation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a navigation apparatus of high precision by considering the characteristics of traffic conditions that change every moment. <P>SOLUTION: Statistical traffic information (statistical data including travel time determined by traffic information collected in the past) is stored in a storage in the navigation apparatus. The version information of map data preserved by oneself is transmitted to a traffic information distribution center. Travel time (travel speed) determined by the current traffic information is included, and current traffic information adapted to the version of the map data is acquired from the traffic information distribution center. Since the travel time of a link whose travel time is unclear is calculated, non-provided link interpolation information is also acquired. A route is searched by using the current traffic information, non-provided link interpolation information, and statistical traffic information. The route is automatically searched when ignition is on. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a navigation device, and more particularly to a route search method for an in-vehicle navigation device.

  Patent Document 1 describes a navigation device that obtains traffic information and searches for a route using the traffic information.

JP 11-83507 A

  However, the navigation device described in Patent Document 1 does not consider the nature of traffic conditions that change every moment.

  For example, when the traffic situation changes and a new road is created, the map data is upgraded. If the map data held by the navigation device is old, it may not be used properly even if current traffic information is obtained. Also, current traffic information is not provided for all roads. Further, as described above, the traffic situation changes every moment.

  The present invention has been made in view of the above circumstances, and is to efficiently obtain and use traffic information in consideration of the properties of traffic information, thereby efficiently and accurately processing a navigation device.

  Specifically, even if the map data held by the navigation device is an old version, it is to efficiently obtain current traffic information and search for a route.

  Further, in route search, a more accurate route search is performed including links for which current traffic information is not provided.

  It is another object of the present invention to provide an easy-to-use navigation device that automatically starts a route search at a timing when a highly accurate recommended route can be provided while taking into consideration the nature of traffic conditions that change every moment.

  In order to solve the above problems, the route searching method of the navigation device of the present invention is configured as follows. The navigation device has a current location detection function. The storage device of the navigation device stores map data including link data of each link constituting a road on the map, and version information of the map data. A starting point / destination setting step for setting a starting point and a destination; a step for transmitting version information of the map data to a traffic information distribution center for distributing traffic information; and a current location detected by the current location detection function The present condition data obtaining step of obtaining present condition data from the traffic information distribution center, which is present condition data determined from the present traffic information of each link existing in the surrounding area of the map, and expressed so as to conform to the version of the map data And a route search step of searching for a recommended route between the departure place and the destination using the map data and the current status data obtained in the current status data acquisition step.

The route searching method of the navigation device of the present invention is configured as follows. The navigation device has a current location detection function. In addition, the storage device of the navigation device stores map data including link data of each link constituting a road on the map. Then, a starting point / destination setting step for setting a starting point and a destination, and a current state for obtaining current state data determined from current traffic information for each link existing in the surrounding area detected by the current point detection function A data acquisition step, an unprovided link interpolation information acquisition step for receiving interpolation information used in determining a route search cost for an unprovided link for which no current data is provided, the map data, and the current data acquisition Using the current state data obtained in the step and the interpolation information obtained in the unprovided link interpolation information obtaining step,
A route search step of searching for a recommended route between the departure point and the destination.

  The route searching method of the navigation device of the present invention is configured as follows. The storage device of the navigation device stores map data including link data of each link constituting a road on the map, and statistical data determined from statistical values of traffic information collected in the past for each link. The statistical data is classified for each traffic information collection condition that is a basis for defining the statistical data. Corresponding to the starting date / destination setting step for setting the starting point and the destination, the map data, the date and time and the situation at the time of passage of each of the route constituting links constituting the route between the starting point and the destination And a route search step for searching for a recommended route between the departure point and the destination using statistical data of the collection conditions to be performed, and the route search step is performed when a guidance route is set when the ignition is ON Perform a reroute search.

  Further, the route search step may be performed when a route searched using statistical traffic data is set as a guide route when the ignition is ON.

  In addition, the route search step may suppress activation of reroute search processing when the time from ignition OFF to ON is a predetermined time or less.

The route searching method of the navigation device of the present invention is configured as follows. The storage device of the navigation device has a current location detection function. Map data including link data of each link constituting a road on the map, and statistical data determined from statistical values of traffic information collected in the past for each link are stored. The statistical data is classified for each traffic information collection condition that is a basis for defining the statistical data. And a departure / destination setting step for setting a departure point and a destination,
Current status data acquisition step for acquiring current status data determined from current traffic information for each link existing in the surrounding area of the current location detected by the current location detection function, and the current status data acquisition step, If acquisition is not complete, use the map data and the statistical data of the collection conditions corresponding to the date and time when each route composing the route constituting the route between the departure point and the destination A route search step for searching for a recommended route between the departure point and the destination, and when the current state data acquisition step completes the acquisition of the current state data of a predetermined link, the map data and the departure point Statistical data of collection conditions corresponding to the date and time of passage of each route constituting link that constitutes the route between the destination and the destination By using the current state data obtained by the current status data obtained step, performing a route search step of searching for a recommended route between the departure point and the destination.

  As described above, according to the present invention, it is possible to search for a route with high accuracy in consideration of the nature of traffic conditions that change every moment.

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram of a navigation system to which an embodiment of the present invention is applied. As shown in the figure, the navigation system of this embodiment includes an in-vehicle navigation device 1000 mounted on a vehicle, a traffic information distribution center 2000 connected via a radio base station 3000 and a network 4000, and an FM multiplex broadcasting station 5000. A beacon 5500, a traffic information management center 6000, and a weather information management center 7000.

  The traffic information management center 6000 manages the latest traffic information in each area, and distributes the traffic information to the traffic information distribution center 2000, the FM multiplex broadcasting station 5000, and the beacon 5500.

  The weather information management center 7000 manages the weather information of each region, and distributes the weather information to the FM multiplex broadcasting station 5000.

  The FM multiplex broadcasting station 5000 performs FM multiplex broadcasting on the rough current traffic data of each mesh area created by dividing the map into a plurality of parts created based on the traffic information of each area distributed from the traffic information management center 6000. Broadcast as a signal. The rough current traffic data includes the link congestion degree determined from the current (latest) traffic information for each link constituting the road existing in the corresponding mesh area. Further, the FM multiplex broadcast station 5000 broadcasts traffic restriction information, which is information on links for which traffic is restricted, as an FM multiplex broadcast signal. Further, the FM multiplex broadcast station 5000 broadcasts the weather information of each area distributed from the weather information management center 7000 as an FM multiplex broadcast signal. Weather information from the weather information management center 7000 may be distributed not from the FM multiplex broadcasting station 5000 but from a traffic information distribution center 2000 described later.

  The beacon 5500 distributes the approximate current traffic information around the area where the beacon is installed to the beacon receiving device 13 described later using radio waves or light as a medium. Radio beacons are mainly installed on highways, and optical beacons are mainly installed on main highways.

  As shown in FIG. 2, the traffic information distribution center 2000 manages current traffic data 2100 for each version 2101 of map data in the database 2010. The current traffic data 2100 is managed for each mesh area (mesh ID) 2102 obtained by dividing the map into a plurality of maps. The current traffic data includes, for each link (link ID) 2103 constituting the road existing in the corresponding mesh area, the link travel time (or link moving speed) determined from the current (latest) traffic information and the link congestion degree. It is out.

  Further, the traffic information distribution center 2000 manages unprovided link interpolation information 2200 for each mesh ID 2203 in the database 2010. Here, the unprovided link interpolation information will be described. The current traffic data is determined from the current traffic information received from a traffic information collection device such as a vehicle detector or a traffic jam detector installed on a specific link. In order to efficiently collect traffic information, the traffic information collecting device is usually installed at a peripheral point where a traffic signal is provided, such as a point where the traffic volume is high or near a main intersection. Accordingly, there is a link (referred to as “unprovided link”) in which the current traffic data 2100 such as travel time (movement speed) is not provided even if a link ID is defined as map data. In the present embodiment, for such an unprovided link, travel time and travel speed are obtained using unprovided link interpolation information. Thereby, a route search including unprovided links can be performed, and a more accurate recommended route search can be performed.

  The unprovided link interpolation information is generated in the traffic information distribution center 2000 based on the current traffic information. Unprovided link interpolation information is generated, for example, from the information calculation unit (not shown) of the traffic information distribution center 2000 as follows. First, for each mesh, the information calculation unit extracts a link having the same attribute in the mesh. Next, an information calculation part calculates | requires average travel time, an average moving speed, etc. for every link of the same attribute from the present condition traffic data of the extracted link. The database 2010 stores the obtained average travel time and average travel speed as interpolation information of unprovided links having the attributes. According to the method for generating unprovided link interpolation information, the unprovided link interpolation information also changes depending on the surrounding situation, for example, the degree of traffic jam. Therefore, it is possible to obtain travel time and moving speed closer to the current traffic situation for the unprovided link. In addition, for unprovided links, it is possible to obtain travel time and moving speed closer to the current traffic situation than using statistical traffic data.

  Examples of the unprovided link interpolation information include a speed parameter 2202 for each road attribute (attributes such as an intercity highway, a national road, and a prefectural road) 2201, a speed parameter for each road width, and the like.

  The vehicle-mounted navigation device 1000 holds statistical traffic data for each mesh area. The statistical traffic data includes the link travel time (or link travel speed) and the degree of link congestion determined from the statistical values of the traffic information collected in the past for each link constituting the road existing in the corresponding mesh area. .

  In the configuration as described above, the in-vehicle navigation device 1000 is wirelessly connected according to the approximate current traffic data of the mesh area corresponding to the current location (own vehicle position) around the FM multiplex broadcasting station 5000 and the beacon 5500. The traffic information distribution center 2000 is accessed via the base station 3000 and the network 4000, and current traffic data in the mesh area corresponding to the current location is obtained. Then, using the current traffic data obtained from the traffic information distribution center 2000 and the statistical traffic data held in advance by the in-vehicle navigation device 1000, a recommended route is searched from the current location to the destination. At this time, in order to determine statistical traffic data to be used, the weather information around the current location received from the FM multiplex broadcasting station 5000 is referred to.

  The traffic information distribution center 2000 has a function for managing current traffic data for each version of map data and each mesh region, and reads the current traffic data of the mesh region requested by the in-vehicle navigation device 1000 to read the in-vehicle navigation device. Any function can be used as long as it has a function of transmitting to 1000 and a function of managing unprovided link interpolation information. Such a traffic information distribution center 2000 can be constructed on a computer system using existing technology, and therefore detailed description thereof is omitted in this embodiment. Further, since the traffic information management center 6000, the weather information management center 7000, the FM multiplex broadcasting station 5000, and the beacon 5500 can also be realized using an existing system, detailed description thereof is omitted.

  Next, the in-vehicle navigation device 1000 will be described in detail. FIG. 3 is a schematic configuration diagram of the in-vehicle navigation device 1000. As shown in the figure, the in-vehicle navigation device 1000 of this embodiment includes an arithmetic processing unit 1, a display 2, a map / statistical traffic data storage device 3, a voice input / output device 4, an input device 5, and a wheel speed. Sensor 6, geomagnetic sensor 7, gyro sensor 8, GPS (Global Positioning System) receiver 9, network connection device 10, in-vehicle LAN device 11, FM multiplex broadcast receiver 12, and beacon receiver 13 Have

  The arithmetic processing unit 1 is a central unit that performs various processes. For example, the present location is detected based on information output from the various sensors 6 to 8 and the GPS receiver 9, and map data necessary for display is obtained from the map / statistical traffic data storage device 3 based on the obtained current location information. read out. Further, the read map data is developed in graphics, and a mark indicating the current location is superimposed on the map data and displayed on the display 2. The destination and current location (departure from the user) using the map data and statistical traffic data stored in the map / statistical traffic data storage device 3 and the current traffic data obtained from the traffic information distribution center 2000. An optimum route (recommended route) is searched for and the user is guided using the voice input / output device 4 and the display 2.

  The display 2 is a unit that displays graphics information generated by the arithmetic processing unit 1, and is configured by a CRT, a liquid crystal display, or the like. The signal S1 between the arithmetic processing unit 1 and the display 2 is generally connected by an RGB signal or an NTSC (National Television System Committee) signal.

  The map / statistical traffic data storage device 3 includes a storage medium such as a CD-ROM, DVD-ROM, HDD, or IC card. In this storage medium, map data and statistical traffic data are stored.

  FIG. 4 is a diagram illustrating a configuration example of map data stored in the map / statistical traffic data storage device 3. As shown in the figure, map data 310 is stored for each mesh region. The map data 310 includes a mesh area identification code (mesh ID) 311 and link data 312 of each link constituting a road included in the mesh area. The link data 312 includes a link identification code (link ID) 3121, coordinate information 3122 of two nodes (start node and end node) constituting the link, road type information 3123 including the link, and a link indicating the link length. Long information 3124, link travel time (or moving speed) information 3125, link ID (connection link ID) 3126 of a link connected to each of the two nodes, and the like. Here, by distinguishing the start node and the end node for the two nodes constituting the link, the upward direction and the downward direction of the same road are managed as different links. The map data 310 also includes information (name, type, coordinate information, etc.) of map components other than roads included in the corresponding mesh area.

  Further, the map / statistical traffic data storage device 3 includes version information 340 that allows the creation time of the map data 310 to be recognized.

  FIG. 5 is a diagram illustrating a configuration example of statistical traffic data stored in the map / statistical traffic data storage device 3. As shown in the figure, statistical traffic data 320 is stored for each mesh region. The statistical traffic data 320 is management data for managing the mesh ID 321 of the mesh area and the traffic information statistical value (statistical value of the traffic information collected in the past) of each link constituting the road included in the mesh area. 322. The mesh ID 321 is the same as the mesh ID 311 of the map data 310. The management data 322 is composed of a plurality of tables 3221 to 3224 having a hierarchical structure.

  The table 3221 is a table for registering the day type. The type of day may be determined for each unit indicating a tendency of different traffic information statistics. Here, weekdays before holidays, “weekdays (before holidays)”, weekdays after holidays, “weekdays (after holidays)”, weekdays before special days such as Bon, New Year, etc. Weekdays of the day of the week “Weekdays (after singular days)”, Other weekdays “Weekdays (general)”, First days of singular days “Holidays (beginning of singular days)”, All day of singular days “Holidays (end of singular days)” The holiday “holiday (general)” is included.

  The table 3222 is a table for registering the weather type, and is provided for each day type registered in the table 3221. The type of weather may be determined for each unit indicating a tendency of different traffic information statistics. Here, “sunny / cloudy”, “rain”, “heavy rain”, “snow”, “heavy snow” are included as the types of weather.

  The table 3223 is a table for registering the link ID of each link constituting the road included in the mesh area registered by the mesh ID 321, and is provided for each type of weather registered in the table 3222. The same link ID as the link ID 3121 of the map data 310 is used.

  The table 3224 is a table for registering traffic information statistical values for each time zone, and is provided for each link ID registered in the table 3223. The traffic information statistics for each time zone include link travel time (or travel speed), link travel time (or travel speed) variability (dispersion), and link congestion specified by the multiple traffic information that is the basis of these statistics. Includes degrees. In addition, the traffic information statistics for each time zone are classified according to the traffic information collection conditions (the type of day and weather type when the basic traffic information is collected) and the target link. That is, the target link of the traffic information statistical value for each time zone registered in a certain table 3224 is a link specified by the link ID of the table 3223 associated with this table 3224, and these statistical values The base traffic information is the weather specified by the weather type in the table 3222 associated with the table 3223 in which the link ID is registered, and the table in which the weather type is registered. 3 is traffic information collected on the day specified by the type of day in the table 3221 associated with 3222.

As described above, the traffic information statistical value includes the degree of link congestion (in FIG. 5, three levels of congestion, congestion, and smoothness). In general, in order to calculate the degree of congestion, it is necessary to compare and determine the speed limit of each link and the moving speed (calculated from the link length and travel time) obtained from the traffic information statistics. By including the congestion degree in the traffic information statistical value in advance, the congestion degree of each link can be determined without using the speed limit information of each link, so that it is not necessary to provide speed limit information in the link data. Thereby, the data size of link data can be made small. Moreover, the information source which is the information about an acquisition source is contained in the traffic information statistical value. By including the information source in the traffic information statistical value in advance and using it for display, it becomes possible to make the user judge the likelihood of the traffic information statistical value.

  Further, the traffic information statistical value includes the degree of dispersion (dispersion degree) of the link travel time specified by the plurality of pieces of traffic information as the basis. By including the degree of variation in the traffic information statistical value in advance and using it for display, it becomes possible for the user to determine the reliability of the link travel time specified from the traffic information statistical value.

  In the map / statistical traffic data storage device 3, in addition to the map data and the statistical traffic data, a conversion table for identifying a mesh ID of a mesh region including a point specified by the coordinate information from the coordinate information. The first conversion table is stored. However, when the mesh ID of the mesh area including the specific point is specified by calculation based on the coordinate information (longitude, latitude, etc.) of the specific point, the first conversion table is not essential. In addition, a second conversion table, which is a conversion table for specifying the type of day managed in the table 3221 from the date, is stored.

  FIG. 6 is a diagram illustrating a configuration example of the second conversion table. As illustrated, a date 331 and a date type 332 corresponding to the date 331 are registered in association with each other. By using such a second conversion table, the type of day can be easily specified from the date. For example, when the process of specifying the day type from the date by calculation logic is executed by the software incorporated in the in-vehicle navigation device, in order to further subdivide the day type classification, the in-vehicle navigation device The embedded software must be rewritten. In addition, the specific processing for special days such as year-end, tray, and GW becomes complicated. In this respect, since the conversion table as shown in FIG. 6 is used in this embodiment, the vehicle-mounted navigation device can be obtained simply by replacing the DVD-ROM or CD-ROM constituting the map / statistical traffic data storage device 3. It is possible to deal with classification subdivisions without changing the software embedded in the. In addition, by making it possible to identify the specific date from the conversion table, it is possible to cope with complicated processing.

  The traffic information distribution center 2000 manages the current traffic data of the corresponding mesh area in association with the mesh ID. This mesh ID is the same as the mesh ID 311 of the map data 310 and the mesh ID 321 of the statistical traffic data 320. The current traffic data is registered for each link in which the link travel time (or link travel time) and the link congestion degree are associated with the link ID. The link ID is the same as the link ID used in the map data 310 and the statistical traffic data 320. The link congestion level is set according to the same standard as the link congestion level used in the statistical traffic data 320.

  Returning to FIG. 3, the description will be continued. The voice input / output device 4 converts the message to the user generated by the arithmetic processing unit 1 into a voice signal and outputs it, and recognizes the voice uttered by the user and transfers the content to the arithmetic processing unit 1.

  The input device 5 is a unit that receives an instruction from a user, and includes a hardware switch such as a scroll key and a scale change key, a joystick, a touch panel pasted on a display, and the like.

  The sensors 6 to 8 and the GPS receiver 9 are used for detecting the current location (own vehicle position) by the vehicle-mounted navigation device. The wheel speed sensor 6 measures the distance from the product of the wheel circumference and the measured number of rotations of the wheel, and further measures the angle at which the moving body is bent from the difference in the number of rotations of the paired wheels. The geomagnetic sensor 7 detects the magnetic field held by the earth and detects the direction in which the moving body is facing. The gyro 8 is configured by an optical fiber gyro, a vibration gyro, or the like, and detects an angle at which the moving body rotates. The GPS receiver 9 receives a signal from a GPS satellite and measures the distance between the mobile body and the GPS satellite and the rate of change of the distance with respect to three or more satellites, so that the current location, travel direction, and travel direction of the mobile body Measure.

  The network connection device 10 controls a wireless communication device such as a mobile phone connected to the in-vehicle navigation device 1000, for example, and the traffic information distribution center 2000 via the wireless base station 3000 and a network such as a public network or the Internet. To access. Then, it communicates with the traffic information distribution center 2000.

  The in-vehicle LAN device 11 receives various information of the vehicle on which the in-vehicle navigation device of the present embodiment is mounted, such as door opening / closing information, light lighting state information, engine status and failure diagnosis result.

  The FM multiplex broadcast receiver 12 receives the approximate current traffic data, traffic regulation information, and weather information sent from the FM multiplex broadcast station 5000 as FM multiplex broadcast signals.

  Here, the rough current traffic data is the mesh ID (the same mesh ID used in the map data, statistical traffic data, and current traffic data) for each mesh area included in the target area (for example, prefecture unit). The link ID of each link included in the mesh area and the link congestion level (set according to the same criteria as the link congestion level used in the statistical traffic data and the current traffic data) are included.

  The traffic regulation information includes the link ID of the regulation target link and the mesh ID of the mesh including the regulation target link.

  The weather information includes the mesh ID of the mesh area included in the target area (for example, by prefecture) (the same mesh ID used in the map data, statistical traffic data, and current traffic data), and the weather in the target area. Type (the type of weather registered in the table 3222 of the statistical traffic data 320) and information on the time zone (called the target time zone) in which the weather continues.

  Note that the weather information is received via the in-vehicle LAN device 11 through the in-vehicle LAN device 11 and the wiper operation status of the vehicle on which the in-vehicle navigation device 1000 is mounted and the detected value of the outside air temperature sensor mounted on the vehicle. The weather may be judged based on the weather.

  The beacon receiving device 13 receives the approximate current traffic data, traffic regulation information, and the like from the beacon 5500 in the same manner as the FM multiplex broadcast receiving device 12.

  FIG. 7 is a diagram illustrating a hardware configuration example of the arithmetic processing unit 1.

  As illustrated, the arithmetic processing unit 1 has a configuration in which devices are connected by a bus 32. The arithmetic processing unit 1 includes a CPU (Central Processing Unit) 21 that executes various processes such as numerical calculation and control of each device, and map data, statistical traffic data, and traffic information read from the map / statistical traffic data storage device 3. A RAM (Random Access Memory) 22 for storing current traffic data and calculation data obtained from the distribution center 2000, a ROM (Read Only Memory) 23 for storing programs and data, and between the memory and each device. DMA (Direct Memory Access) 24 for executing data transfer, a drawing controller 25 for executing graphics drawing and controlling display, a video random access memory (VRAM) 26 for storing graphics image data, and image data Color palette 27 for converting to RGB signal and A / for converting analog signal to digital signal A converter 28; an SCI (Serial Communication Interface) 29 for converting a serial signal into a parallel signal synchronized with the bus; a PIO (Parallel Input / Output) 30 for synchronizing the parallel signal with the bus; And a counter 31 for integrating the signal.

  FIG. 8 is a diagram illustrating a functional configuration of the arithmetic processing unit 1.

  As shown in the figure, the calculation processing unit 1 includes a user operation analysis unit 41, a route search unit 42, a route / current traffic data storage unit 43, a route guidance unit 44, a map display processing unit 45, and a current position calculation. Unit 46, map match processing unit 47, data reading unit 48, trajectory storage unit 49, menu display processing unit 50, graphics processing unit 51, current traffic data update unit 52, network communication unit 55, And an unprovided link interpolation information storage unit 53.

  The current position calculation unit 46 uses distance data and angle data obtained as a result of integrating the distance pulse data S5 measured by the wheel speed sensor 6 and the angular acceleration data S7 measured by the gyro 8, respectively. The current position (X ′, Y ′), which is the position after the vehicle travels, is periodically calculated from the initial position (X, Y) and is output to the map match processing unit 47. . Here, in order to make the relationship between the rotation angle of the host vehicle and the traveling direction coincide, reference is made to the direction data S6 obtained from the geomagnetic sensor 7 and the angle data obtained by integrating the angular acceleration data S7 obtained from the gyro 8. Estimate the absolute direction of the direction in which the vehicle is traveling. In addition, since the error accumulates when the data of the wheel speed sensor 6 and the data of the gyro 8 are respectively integrated, the error accumulated based on the position data S8 obtained from the GPS receiver 9 in a certain time period is calculated. Processing for canceling is performed, and information on the current location is output to the map match processing unit 47.

  The map match processing unit 47 compares the map data around the current location read by the data reading unit 48 with the travel locus stored in the locus storage unit 49 described later, and the road (link) having the highest shape correlation. In addition, a map matching process is performed in which the current location periodically output from the current position calculation unit 46 is matched. Since the current position information obtained by the current position calculation unit 46 includes a sensor error, map matching processing is performed for the purpose of further improving the position accuracy. As a result, the current location often coincides with the traveling road.

  The trajectory storage unit 49 stores information on the current location on which the map match processing has been performed by the map match processing unit 47 as trajectory data every time the vehicle travels a predetermined distance. The trajectory data is used to draw a trajectory mark on the road on the map corresponding to the road that has been traveled so far.

  The user operation analysis unit 41 receives a request from the user input to the input device 5, analyzes the request content, and controls each unit of the arithmetic processing unit 1 so that processing corresponding to the request content is executed. To do. For example, when the user requests a search for a recommended route, the map display unit 45 is requested to display a map on the display 2 in order to set a destination, and further, from the current location (departure location) to the destination. Requests the route search unit 42 to calculate a route.

  The current traffic data update unit 52 acquires the current traffic data from the traffic information distribution center 2000 via the network connection device 10 and updates the current traffic data stored in the route / current traffic data storage unit 43.

  The route search unit 42 uses the Dijkstra method or the like, and has the least route (cost (travel time)) that can reach the destination in the shortest time among the routes connecting the two specified points (current location, destination). Route) is retrieved from the map data, and the route obtained as a result is stored in the route / current traffic data storage unit 43 as a recommended route. In this embodiment, the statistical traffic data stored in the map / statistical traffic data storage device 3 and the current traffic stored in the route / present traffic data storage unit 43 are used to calculate the cost of the route connecting the two points. Data is used. The route search unit 42 also performs processing for obtaining predicted travel time / expected arrival time, reliability / estimation error, and a congestion level display section / congestion level of each section.

  The route guidance unit 44 compares the recommended route information stored in the route / current traffic data storage unit 43 with the current location information output from the map match processing unit 47, and should proceed straight before passing the intersection. The voice input / output device 4 is used to inform the user by voice whether to turn left or right. Also. The direction to be advanced is displayed on the map displayed on the display 2, and the recommended route is notified to the user.

  Further, the route guidance unit 44 uses the statistical traffic data stored in the map / statistical traffic data storage device 3 and the current traffic data stored in the route / current traffic data storage unit 43 to use the map match processing unit 47. Calculate the estimated travel time from your current location to your destination. Then, by adding the calculated estimated travel time to the current time, an expected arrival time at the destination is calculated and notified to the user.

  Furthermore, the route guidance unit 44 measures the actual travel time required from the departure point of the recommended route to the current location output from the map match processing unit 47. Then, the travel time is compared with the cost of the section from the departure point to the current location in the cost (travel time) used by the route search unit 42 for searching for the recommended route, and the comparison result is determined. To determine the necessity of re-searching the recommended route. If it is determined that there is a need for re-search, the route search unit 42 is requested to re-search for a recommended route with the current location output from the map match processing unit 47 as the departure location and the current time as the departure time.

  The data reading unit 48 displays map data and statistical traffic data in an area required to be displayed on the display 2 and an area required for route search (an area including a starting point and a destination) as map / statistics. It operates to prepare for reading from the traffic data storage device 3.

  The map display processing unit 45 receives the map data in the area where the display on the display 2 is requested from the map / statistical traffic data storage device 3, and the graphic processing unit 51 uses the designated scale and drawing method for the road, A map drawing command is generated so as to draw other map components and marks such as current location, destination, and an arrow for a guide route. Further, in response to a command output from the user operation analysis unit 41, statistical traffic data that is requested to be displayed on the display 2 is received from the map / statistical traffic data storage device 3, and display on the display 2 is requested. Current traffic data is received from the route / current traffic data storage unit 43, and a map drawing command is generated so that the traffic information of each road is displayed on the map being displayed on the display 2.

  Upon receiving a command output from the user operation analysis unit 41, the menu display processing unit 50 generates a menu drawing command so that the graphic processing unit 51 draws various types of menus and graphs.

  The graphics processing unit 51 receives commands generated by the map display processing unit 45 and the menu display processing unit 50 and develops image data to be displayed on the display 2 on the VRAM 26.

  The network communication unit 55 receives traffic-related information such as current traffic data and unprovided link interpolation information from the traffic information distribution center 2000 via the network connection device 10, the wireless base station 3000, and the network 4000.

  The unprovided link interpolation information storage unit 53 stores unprovided link interpolation information distributed from the traffic information distribution center 2000 and received via the network connection device 10, the FM multiplex broadcast receiving device 12, the beacon receiving device, and the like.

  (Description of Operation) Next, the operation of the in-vehicle navigation device 1000 will be described. FIG. 9 is a flowchart showing an outline of the operation of the in-vehicle navigation device 1000 of the present embodiment.

  This flow is started when the user operation analysis unit 41 receives a request for searching for a recommended route or a calculation of an estimated travel time from the user via the voice input / output device 4 or the input device 5. Then, departure point setting, destination setting, departure time setting (S100), route search (S101), and recommended route display display (S105) are performed.

  As shown in FIG. 10, the route search process (S101) includes a search process that uses only statistical traffic data (route search process A) (S103), and a search process that uses statistical traffic data and current traffic data (route search). Process B) (S104). These will be described later.

  (Timing for Starting Route Search) In FIG. 9, the route search is performed after the user receives the departure place setting, the destination setting, and the departure time setting. However, the present embodiment is not limited to this.

  For example, the route search may be automatically started when the ignition (IGN) is turned on. FIG. 11 is a flowchart showing a flow of automatically starting a route search when a guidance route is set when the ignition is ON. In this case, the vehicle-mounted navigation apparatus 1000 determines that the ignition is on, triggered by the start of power supply by the battery. In this flow, first, the route search unit 42 confirms that the ignition is ON, and then determines whether or not a predetermined time (a time during which traffic conditions seem to be unchanged, for example, 20 minutes) has elapsed from ignition OFF to ON. (S10012). If the predetermined time has not elapsed, the route search unit 42 ends this flow and returns to normal processing. If the predetermined time has elapsed (Yes in S10012), the route search unit 42 determines whether a guidance route is set (S10013). When the guidance route is not set, the route search unit 42 ends the process. When the guidance route is set, the route search unit 42 starts the route search using the departure point as the current location and the departure time as the current time (S10014). According to this flow, when a predetermined time elapses from ignition OFF to ON and a guidance route is set, the route search is automatically started after the ignition is turned on (S10014). Therefore, since the recommended route at the time when the user resumes the travel is automatically searched, the recommended route with higher accuracy in consideration of the latest current traffic data is provided to the user. Further, since the re-route search is not performed at the time when the traffic situation is considered to be unchanged, the processing load on the navigation device 1000 can be reduced. Specifically, this will be described using the following example.

  Usually, when starting a trip toward a destination, a user searches for a recommended route before the trip and sets the searched recommended route as a guidance route. The navigation device 1000 displays the set guidance route. The user starts a trip according to the displayed guidance route. Here, it is common for the user to stop for a break in a parking area or the like before arriving at the destination. Then, after taking a break in the parking area, the user starts driving toward the destination again. In the above travel mode, if the break time is long, the traffic situation may change greatly during that time. In such a case, the guidance route set before the trip may not necessarily be the optimum route. On the other hand, according to the flow shown in FIG. 11, if the ignition of the car is turned on after the break, the route search is automatically performed again. Therefore, even when the current traffic situation changes greatly, it is possible to provide the user with a recommended route in consideration thereof. On the other hand, if it is a short time from when the ignition is turned off to when it is turned on (for example, when the break time is short), the current traffic situation seems not to change, so the route search is not performed again. . Thereby, it is possible to prevent the navigation apparatus 1000 from performing useless processing.

  As shown in FIG. 12, when the route searched using only statistical traffic data is selected in advance when the ignition is ON (S10021), for example, the route search is performed using only statistical traffic data. If the result is displayed (Yes in S10022), after the ignition is turned on, the current traffic data is obtained (S10023), and the route search is started using the obtained current traffic data (S10025). Good. In this flow, the route search unit 42 searches for a route using only the statistical traffic data from the user whether or not the route searched using only the statistical traffic data is selected in advance. Determine if the result is requested to be displayed. According to this flow, since the route search considering the current traffic data is performed at the same time as the ignition is turned on, it is convenient for the user and provides a more accurate route search result.

  Further, the route search process may proceed as shown in the flowchart of FIG. In this flow, first, after setting a departure place, a destination, and the like (S10031), acquisition of current traffic data is started (S10032). Until the acquisition of the current traffic data is completed (or the acquisition of the current traffic data of a predetermined amount or more. The same applies hereinafter), route search processing using only statistical traffic data is performed (S10033), and the search result is displayed. (S10034). When the acquisition of the current traffic data is completed (Yes in S10035), a route search process using the statistical traffic data and the current traffic data is performed (S10036). Then, the result is displayed (S10037). The amount of current traffic data obtained may be determined in advance depending on the purpose of route search and the current traffic data acquisition method. You may let them. For example, when the current traffic data is obtained for a link that can be reached from the departure time to a time when there is no change in the traffic situation, it can be determined that the acquisition of the current traffic data is completed. In addition, when the information of each link within a predetermined range (for example, within 10 km) from the departure place is obtained, the information of each link whose estimated arrival time is within the predetermined range (for example, within one hour) When it is obtained, it may be determined that the acquisition of traffic data is completed. Depending on the purpose of the route search, when the current traffic data in a range where the purpose can be achieved is obtained, the acquisition may be completed. For example, when the route search is performed only on the main road, it can be determined that the acquisition is completed when the current traffic data of the main road around the departure point is acquired. If the current traffic data acquisition source is the FM multiplex broadcasting station 5000 or the beacon 5500, it may be determined that the acquisition has been completed when the current traffic data that can be received at that time is acquired.

  According to this flow, even if it takes time to obtain the current traffic data due to the influence of the communication means or the like, the route search can be performed using the statistical traffic data stored in advance, and the recommended route can be displayed. Then, as soon as the current traffic data is obtained, the route search using the current traffic data is performed again, so that the route search result with high accuracy is finally displayed. Therefore, the user does not have to wait for a long time until the route search result is displayed, and the route search result with high accuracy is finally obtained, which is convenient for the user.

  Returning to FIG. Each process will be specifically described below.

  In the departure point, destination and departure time setting process (S100), the user operation analysis unit 41 sets the departure point, destination and departure time in the route search unit 42. Specifically, the current location output from the map match processing unit 47 when a search request for a recommended route is received is set as the departure location. When the current time is set as the departure time, the current time acquired when the recommended route search request is received is set as the departure time using a built-in timer (not shown). The destination is set based on a user instruction. For example, the user operation analysis unit 41 is registered in the display 2 through the menu display processing unit 50 and the graphics processing unit 51, and registered in the map data read from the map / statistical traffic data storage device 3 through the data reading unit 48. The information of the existing map constituent is displayed, and the user selects the destination from the information of the displayed map constituent via the voice input / output device 4 or the input device 5. Alternatively, information on a location (registration location) registered in advance in a storage device such as the RAM 22 is displayed by the user, and information on the registered location being displayed is displayed by the user via the voice input / output device 4 or the input device 5. Lets you select a destination from the inside. Furthermore, the user operation analysis unit 41 specifies the map data read from the map / statistical traffic data storage device 3 via the data reading unit 48 on the display 2 via the map display processing unit 45 and the graphics processing unit 51. The destination map is displayed, and a destination is selected by receiving designation of a point on the map from the user via the voice input / output device 4 or the input device 5.

  (Route Search Process) Next, the route search process (S101) will be described. The following is an example of route search processing.

  As shown in FIG. 10, the route search process described here includes a search process using only statistical traffic data (route search process A) and a search process using statistical traffic data and current traffic data (route search process). B).

  First, the update operation of the current traffic data used in the route search process B will be described. FIG. 14 is a flowchart for explaining the current traffic data update operation.

  First, the current traffic data updating unit 52 reads the first conversion table from the map / statistical traffic data storage device 3 via the data reading unit 48. And the mesh ID of the mesh area | region containing the present location periphery output from the map match process part 47 is specified using a 1st conversion table. Then, the current traffic data update unit 52 includes the rough current traffic data having the mesh ID of the mesh area including the current location area in the rough current traffic data received from the FM multiplex broadcast station 5000 via the FM multiplex broadcast receiver 12. Is included (S301).

  If the approximate current traffic data received from the FM multiplex broadcast station 5000 includes the approximate current traffic data having the mesh ID of the mesh area including the current location (Yes in S301), the current traffic data update unit 52 It is checked whether or not the current traffic data having the mesh ID of the mesh area including the current location periphery is already stored in the route / current traffic data storage unit 43 (S302).

  In S302, when the current traffic data having the mesh ID of the mesh area including the current location periphery is already stored, the current traffic data update unit 52 obtains the previous current traffic data by using a not-shown built-in timer or the like. Thereafter, it is further examined whether or not a first predetermined time (a time interval during which a change in traffic conditions cannot be expected in a shorter time, for example, 10 minutes) has passed (S303). When the first predetermined time has elapsed (Yes in S303), the current traffic data update unit 52 determines the link congestion level indicated by the approximate current traffic data for each link included in the mesh area including the current location and its surroundings. The difference with the link congestion degree indicated by the current traffic data is obtained. Then, it is further examined whether or not the number of links whose links are larger than a predetermined value (or the ratio of the number of links to the total number of links included in the mesh area including the vicinity of the current location) is greater than a predetermined threshold (S304). ).

  The current traffic data update unit 52 determines that the number of links whose difference is larger than a predetermined value (or the ratio of the number of links to the total number of links included in the mesh area including the current location) is the predetermined threshold value. If there are more (Yes in S304), the traffic information distribution center 2000 is accessed via the network connection device 10, and the current traffic data having the mesh ID of the mesh area including the periphery of the current location is obtained from the traffic information distribution center 2000. The obtained current traffic data is stored in the route / current traffic data storage unit 43 (S311). Then, the process proceeds to S312.

  On the other hand, the current traffic data update unit 52 determines whether the first predetermined time has not elapsed since the previous current traffic data was acquired (No in S303), or the number of links of the links whose difference is greater than the predetermined value ( Alternatively, when the ratio of the number of links to the total links included in the mesh area including the current location periphery is smaller than the predetermined threshold (No in S304), the process proceeds to S309.

  In S302, when the current traffic data having the mesh ID of the mesh region including the current location periphery is not yet stored in the route / current traffic data storage unit 43, the current traffic data update unit 52 passes through the FM multiplex broadcast receiving device 12. Then, from the FM multiplex broadcasting station 5000, the mesh ID of the mesh area including the current location and the weather information of the time zone including the current time are obtained (S305). Note that the weather may be determined from the wiper operation status information and the outside air temperature information received via the in-vehicle LAN device 11, and the determination result may be used as the weather information.

  Next, the current traffic data updating unit 52 reads the second conversion table from the map / statistical traffic data storage device 3 via the data reading unit 48. Then, the type of today's (departure date) day is specified using the second conversion table (S306). In addition, when today's date is not registered in the second conversion table, processing for identifying the day type from the date by calculation logic is executed by software built in the vehicle-mounted navigation device, You may make it identify the kind of corresponding day. In this way, even when the date range registered in the second conversion table is exceeded, the process can be continuously executed.

  Next, the current traffic data update unit 52 reads the statistical traffic data 320 having the mesh ID of the mesh area including the periphery of the current location from the map / statistical traffic data storage device 3 via the data reading unit 48. Then, from the read statistical traffic data 320, for each link associated with the type of day specified in S305 and the type of weather specified by the weather information acquired in S306, traffic information in the time zone including the current time A statistical value is specified (S307).

  Then, the current traffic data update unit 52 calculates, for each link included in the mesh region including the periphery of the current location, a difference between the link congestion level indicated by the approximate current traffic data and the link congestion level indicated by the specified traffic information statistical value. Ask. Then, it is further checked whether or not the number of links whose links are larger than a predetermined value (or the ratio of the number of links to the total number of links included in the mesh area including the vicinity of the current location) is greater than a predetermined threshold (S308). ).

  In S308, if the number of links of the link whose difference is larger than a predetermined value (or the ratio of the number of links to the total number of links included in the mesh area including the vicinity of the current location) is greater than the predetermined threshold, The traffic data update unit 52 proceeds to S311 and stores the current traffic data having the mesh ID of the mesh area including the current location and the surrounding area obtained from the traffic information distribution center 2000 in the route / current traffic data storage unit 43 (S311). . Then, the process proceeds to S312. On the other hand, if it is less than the predetermined threshold value, the process proceeds to S309.

  Next, in S309, the current traffic data update unit 52 includes a traffic having the mesh ID of the mesh area including the current location in the traffic regulation information received from the FM multiplex broadcast station 5000 via the FM multiplex broadcast receiver 12. It is checked whether or not regulation information is included or whether or not a change has occurred in the traffic regulation information. If it is included or has changed, the current traffic data update unit 52 proceeds to S311 and obtains the current traffic data having the mesh ID of the mesh area including the periphery of the current location obtained from the traffic information distribution center 2000 as the route / current traffic. The data is stored in the data storage unit 43 (S311). Then, the process proceeds to S312. On the other hand, if it is not included or does not change, the process proceeds to S310.

  Next, in S310, the current traffic data update unit 52 uses a built-in timer (not shown) or the like to obtain the current traffic data for the second time (at a time interval at which traffic conditions can be expected to change). Then, it is checked whether or not a time longer than the first predetermined time (for example, 30 minutes) has elapsed. When the second predetermined time has elapsed (Yes in S310), the current traffic data update unit 52 proceeds to S311 and has the current status having the mesh ID of the mesh region including the current location and the surrounding area obtained from the traffic information distribution center 2000. The traffic data is stored in the route / current traffic data storage unit 43 (S311). Then, the process proceeds to S312. On the other hand, if the second predetermined time has not elapsed (No in S310), the process immediately proceeds to S312.

  In step S312, the current traffic data update unit 52 uses a built-in timer (not shown) or the like for a third predetermined time (a time interval at which the update of the approximate current traffic data can be expected and is shorter than the first predetermined time). , For example, 5 minutes), and the process returns to S301.

  According to this flow, when (1) the link congestion degree indicated by the statistical traffic data is different from the link congestion degree indicated by the latest approximate current traffic data, (2) the current status stored in the route / current traffic data storage unit 43 If the link congestion degree indicated by the traffic data is different from the link congestion degree indicated by the latest approximate current traffic data, (3) if traffic regulation information around the current location is obtained, (4) since the current traffic data was obtained last time When the second predetermined time has passed, if any of the cases corresponds to one, new current traffic data is obtained and stored in the route / current traffic data storage unit 43. However, the current traffic data is not obtained if the first predetermined time has not elapsed since the current traffic data was previously acquired. By doing so, it is possible to prevent the current traffic data from becoming too old while the frequency of access to the traffic information distribution center 2000 is suppressed.

  Although an example of the update operation of the current traffic data has been described above, the present embodiment is not limited to this. The approximate current traffic data can also be obtained from the beacon 5500 via the beacon receiver 13. In addition, the current traffic data may be obtained as follows.

  The current traffic data is obtained by the network communication unit 55 via the network connection device 10, the wireless base station 3000, and the network 4000. In this case, as shown in FIG. 15, the network communication unit 55 first sends the version information 340 of the map data 310 held by itself to the traffic information distribution center 2000. In response to this, the traffic information distribution center 2000 sends the current traffic data conforming to the map data version to the network communication unit 55. Thereby, even if the map data which the vehicle-mounted navigation apparatus 1000 has is an old version, it is possible to receive current traffic data that conforms to the old version of map data. Specifically, for example, the map data 310 held by the in-vehicle navigation device 1000 is an old version, and in the old version map data, a road was treated as one link, but in the new version map data, 2 May be treated as a link. In such a case, both the current traffic data expressed by the old version link and the current traffic data expressed by the new version link are received at the same time, and only the current traffic data expressed by the old version link from among them is received. If it is adopted, the processing efficiency is poor. On the other hand, if the traffic information distribution center 2000 is informed in advance that the map data of the old version is held, only the current traffic data expressed by the link of the old version can be efficiently obtained, and a quick process can be performed. Will be able to.

  In the above, the update process of the present traffic data was demonstrated.

  Next, route search processing will be described with reference to the flowchart of FIG.

  First, the route search unit 42 checks whether or not the current traffic data having the mesh ID of the mesh region including the current location periphery is stored in the route / current traffic data storage unit 43 (S102). If not stored, the process proceeds to S103, and a recommended route is searched using the statistical traffic data stored in the map / statistical traffic data storage device 3 (route search processing A). On the other hand, if it is stored, the process proceeds to S104, and the current traffic data stored in the route / current traffic data storage unit 43 and the statistical traffic data stored in the map / statistical traffic data storage device 3 are used. To search for a recommended route (route search processing B).

  Next, the route search process A will be described. FIG. 16 is a flowchart for explaining the process (route search process A) in S103 of FIG.

  First, the route search unit 42 reads the first conversion table from the map / statistical traffic data storage device 3 via the data reading unit 48. Using the read first conversion table, the mesh ID of each mesh region included in the region including the set departure place and destination is specified. Then, each link data 312 registered in each map data 310 having the identified mesh ID is obtained from the map / statistical traffic data storage device 3 via the data reading unit 48. In addition, the route search unit 42 reads the second conversion table from the map / statistical traffic data storage device 3 via the data reading unit 48. And the kind of day of departure date is specified using the 2nd conversion table. If the date of departure is not registered in the second conversion table, the process of specifying the day type from the date by the calculation logic is executed by the software incorporated in the in-vehicle navigation device. You may make it identify the kind of day corresponding to a day. In this way, even when the date range registered in the second conversion table is exceeded, the process can be continuously executed (S10301).

  Next, the route search unit 42 uses the link data 312 read from the map / statistical traffic data storage device 3 in S10301 to determine the end node of the link (referred to as an extracted link) extracted from the heap table in S10308 to be described later. A link as a start node is selected as a candidate for a link that constitutes a recommended route (referred to as a candidate link). However, when the processing in S10308 is not performed, that is, in the initial stage where the link is not registered in the heap table, instead of selecting a link having the end node of the extracted link as a start node as a candidate link, the departure place Is selected as a candidate link (S10302).

  Here, the heap table is a table for registering the link data of the candidate link together with the total cost (total travel time) from the departure place to the end node of the candidate link, and is stored in a storage device such as a memory. The

  Next, the route search unit 42 calculates the estimated arrival time at the end node of the extracted link. This can be calculated by adding the total cost (total travel time) of the extraction links registered in the heap table to the departure time. In addition, the route search unit 42 identifies the mesh ID of the mesh region where the end node of the extraction link is located using the first conversion table. However, when the process in S10308 is not performed, that is, in the initial stage where the link is not registered in the heap table, the mesh ID of the mesh area where the departure point is located is specified. Then, the route search unit 42 has the identified mesh ID and a target time zone (referred to as an attention time zone) to which the estimated arrival time at the end node of the extraction link belongs via the FM multiplex broadcast receiving device 12. Weather information is obtained (S10303). Note that the weather may be determined from the wiper operation status information and the outside air temperature information received via the in-vehicle LAN device 11, and the determination result may be used as the weather information.

  Next, the route search unit 42 accesses the statistical traffic data 320 having the mesh ID specified in S10303 stored in the map / statistical traffic data storage device 3 via the data reading unit 48. Then, using the management data 322 of the statistical traffic data 320, for each candidate link, the traffic information statistical value of the attention time zone is specified by the type of day specified in S10301 and the weather information acquired in S10303. The traffic information statistical value associated with the type of weather to be obtained is obtained (S10304).

  Then, the route search unit 42 obtains the cost (travel time) of the candidate link by using the traffic information statistical value obtained in S10304 for each candidate link (S10305). When travel time is included in the traffic information statistics, this is used as the cost. When the travel speed is included instead of the travel time, the travel time of the link is calculated using the travel speed and the link length specified from the link data 312 and is used as the cost. If there is a candidate link for which traffic information statistics could not be obtained in S10304, the travel time included in the link data 312 of this link candidate or the travel included in the link data 312 The travel time of the link calculated using the speed and the link length is set as the cost of the candidate link.

  Next, the route search unit 42 calculates the total cost of each candidate link (total travel time from the departure point to the end node of the candidate link). Specifically, the cost of the candidate link calculated in S10305 is added to the total cost of the extracted link registered in the heap table, and the addition result is set as the total cost of the candidate link. However, at the initial stage where the extraction link is not registered in the heap table, the cost of the candidate link calculated in S10305 is set as the total cost of the candidate link. Then, the route search unit 42 adds the link data and the total cost of each candidate link to the heap table (S10306).

  Next, the route search unit 42 determines whether there is a link where the destination exists or is close to the destination (called a destination link) among the links newly added to the heap table in S10306 performed immediately before. It is checked whether or not (S10307).

  If it is determined that there is no destination link (No in S10307), the route search unit 42 sorts the information of the unextracted links registered in the heap table in ascending order of the total cost, and extracts the first link located For example, the unextracted link with the minimum total cost is extracted from the heap table (S10308). Then, the process returns to S10302.

  On the other hand, when it is determined that there is a destination link (Yes in S10307), the route search unit 42 performs recommended route determination processing. Specifically, the heap table is searched for a link that has generated the destination link (a link having the start node of the destination link as the end node), and the detected link is determined as a constituent link that constitutes the recommended route. Next, it is checked whether or not the constituent link is a starting point link that exists or is close to the starting point. If it is not a starting point link, the link that generated this constituent link is searched and the detected link is detected. Is determined as a constituent link, and it is further examined whether or not it is a departure link. By repeating this process until it is determined that the configuration link is the departure link, each configuration link that constitutes the recommended route is determined. Then, the route search unit 42 stores the link data 312 and the traffic information statistics obtained in S10304 in the route / present traffic data storage unit 43 for each of the constituent links constituting the recommended route (S10309).

  As described above, the travel time of each constituent link constituting the recommended route is as follows. That is, the travel time obtained from the traffic information statistics corresponding to the time zone including the departure time (current time) is used as the travel time of the first link constituting the recommended route. In addition, the travel time of the nth (n ≧ 2) link constituting the recommended route corresponds to a time zone including an expected arrival time at the end node of the n−1th link connected to the nth link. The travel time obtained from the traffic information statistics is used.

  Next, the route search process B will be described. FIG. 17 is a flowchart for explaining the process (route search process B) in S104 of FIG.

  First, the route search unit 42 obtains each link data 312 of each mesh region included in the region including the departure place and the destination by the same process as S10301 in FIG. In addition, the type of today's (departure date) day is specified (S10401).

  Next, the route search unit 42 uses each link data 312 obtained in S10401, and uses the link starting from the end node of the extracted link extracted from the heap table in S10409, which will be described later, as candidates for configuring the recommended route. Elect as a link. However, when the processing in S10409 is not performed, that is, in the initial stage in which no link is registered in the heap table, instead of selecting a link having the extraction link end node as a start node as a candidate link, the departure place Is selected as a candidate link (S10402).

  Next, the cost of each candidate link is calculated (S10420). FIG. 18 shows the flow of the cost calculation process for each candidate link.

  First, the route search unit 42 determines whether the candidate link is a link existing in the area where the current traffic data is obtained (S10421). When the candidate link is not a link that exists in the area where the current traffic data is obtained (No in S10421), the route search unit 42 uses the statistical traffic data to calculate the cost of the candidate link as in S10403 to S10405 of FIG. Calculation is performed (S10425). On the other hand, when the candidate link is a link existing in the area where the current traffic data is obtained (Yes in S10421), the route search unit 42 adds the current traffic data stored in the route / current traffic data storage unit 43 to the current traffic data. It is checked whether the link travel time (or link moving speed) of the candidate link is included (S10423). If it is included (Yes in S10423), the route search unit 42 obtains the link travel time of the candidate link from the current traffic data stored in the route / current traffic data storage unit 43. Alternatively, the link moving speed of the candidate link is obtained. The link travel speed of the candidate link is calculated using the link moving speed of the candidate link and the link length included in the link data 312 of the candidate link, and the link travel time of the candidate link is calculated as the cost of the candidate link. (S10426).

  On the other hand, when the current travel data stored in the route / current traffic data storage unit 43 does not include the link travel time (or the link travel speed) of the candidate link (No in S10423), the unprovided link interpolation information is included. It is checked whether it is provided (S10424). When the unprovided link interpolation information is not provided (No in S10424), the route search unit 42 calculates the cost of the candidate link using the statistical traffic data (S10425). On the other hand, when the unprovided link interpolation information is provided (Yes in S10424), the route search unit 42 calculates the travel time and the like using the unprovided link interpolation information, and then calculates the cost of the candidate link (S10427). ).

  For example, the travel time is calculated using the unprovided link interpolation information as follows. When speed parameters according to road attributes (attributes such as intercity highways, national roads, and prefectural roads) are provided as unprovided link interpolation information, it is first determined which road the candidate link belongs to. Next, the speed parameter corresponding to the attribute is searched from the unprovided link interpolation information storage unit 53. Then, the travel time is calculated using the retrieved speed parameter. When the speed parameter is the average speed of links having the same attribute, the average speed is set as the moving speed of the unprovided link. When the speed parameter for each road width is provided as the unprovided link interpolation information, the travel time for the unprovided link can be obtained in the same manner as described above even when the speed parameter for each congestion degree is provided.

  The process shown in FIG. 18 is performed for each candidate link. According to the above flow, the cost of a candidate link is calculated using the current traffic data, unprovided link interpolation information, and statistical traffic data in order in the order of the departure point (current location). For the distance from the departure point (current location), the cost of the candidate link is calculated using the statistical traffic data. Therefore, a highly accurate link cost can be provided.

  In S10423, when it is determined that the current traffic data stored in the route / current traffic data storage unit 43 includes the link travel time (or link travel speed) of the candidate link (Yes in S10423), the following You may make it process. First, the route search unit 42 calculates the estimated arrival time at the end node of the extracted link. Then, it is further examined whether or not the difference between the predicted arrival time and the current time is within a predetermined value. Here, the predetermined value has changed significantly from the traffic situation indicated by the current traffic data even after the predetermined value has elapsed since the current time, which is considered too short for a significant change in traffic conditions. It may be set to a time (eg, 30 minutes) that is considered not to be present. The difference between the predicted arrival time at the end node of the extracted link and the current time is greater than or equal to a predetermined value, and the traffic situation at the expected arrival time is likely to have changed significantly from the traffic situation indicated by the current traffic data. If it is determined, the route search unit 42 proceeds to S10425 and performs the same processing as S10403 to S10405 of FIG. Thereby, the cost of each candidate link is calculated using the traffic information statistical value of the statistical traffic data.

  Returning to FIG. The route search unit 42 calculates the total cost of each candidate link (total travel time from the departure point to the end node of the candidate link). Specifically, the cost of the candidate link calculated in S10425, S10426, or S10427 is added to the total cost of the extracted link registered in the heap table, and the addition result is set as the total cost of the candidate link. However, at the initial stage where the extraction link is not registered in the heap table, the cost of the candidate link calculated in S10425, S10426, or S10427 is set as the total cost of the candidate link. Then, the route search unit 42 adds the link data and the total cost of each candidate link to the heap table (S10407).

  Next, the route search unit 42 checks whether there is a destination link among the links newly added to the heap table in S10407 performed immediately before (S10408).

  When it is determined that there is no destination link (No in S10408), the route search unit 42 sorts the link information registered in the heap table in ascending order of the total cost, and extracts the first position link. Thus, a candidate link with the minimum total cost is extracted from the heap table (S10409). Then, the process returns to S10402.

  On the other hand, if it is determined that there is a destination link (Yes in S10408), the route search unit 42 determines a recommended route by the same process as S10309 in FIG. The data 312 and traffic information statistics or current traffic data are stored in the route / current traffic data storage unit 43 (S10410).

  Although the route search processing (route search processing A and route search processing B) has been described above, the route search processing applicable to the present invention is not limited to the above. In the above route search processing, the mesh ID of each mesh region included in the region including the departure place and the destination is specified using the first conversion table. The present embodiment is not limited to this, and the corresponding mesh ID may be specified by calculation based on the position information (longitude, latitude) without using the first conversion table. In addition, other route search methods can be employed as long as the present invention can be implemented within the scope of the gist thereof. For example, a route search method in which all routes from the starting point to the destination included in the assumed mesh region are searched by the brute force method using the Dijkstra method, and then the route having the shortest travel time is searched for in the route. May be adopted. Even in this case, for the unprovided link, it is possible to perform a route search including the unprovided link by calculating the travel time using the unprovided link interpolation information.

  The recommended route may be a route that takes the shortest travel time between the departure point and the destination under specific conditions. For example, a route searched under conditions according to the user's preference, such as excluding a highway, making the route search result a recommended route, or excluding a specific local link, making the route search result a recommended route, etc. It may be a recommended route.

  (Processing for Estimated Travel Time / Estimated Arrival Time) The process for obtaining the estimated travel time and the like has been outlined in the route search process described above. That is, the route search unit 42 uses the link data and the traffic information statistical value or the current traffic data of each link constituting the recommended route registered in the route / current traffic data storage unit 43, so that S10305 in FIG. The cost of each link is calculated by the same processing as 18 of S10425, S10426, and S10427. Then, the total cost of each link constituting the recommended route is set as the expected travel time of the recommended route. Further, a time obtained by adding the estimated travel time to the departure time (current time) is set as an estimated arrival time at the destination.

  (Process for Obtaining Reliability / Estimation Error) Next, a process for obtaining the reliability / estimation error of the expected travel time and the expected arrival time will be described.

  The route search unit 42 uses each degree of variation included in the traffic information statistical value of each link constituting the recommended route registered in the route search unit route / present traffic data storage unit 43 to each link constituting the recommended route. The cost error is calculated. For example, when the degree of variation is “small”, the error rate is 3%, when the degree of variation is “medium”, the error rate is 5%, and when the degree of variation is “large”, the error rate is 10%. Then, the error of the link is calculated by multiplying the cost of the link by the error rate corresponding to the degree of variation of the link. This process is performed for each link constituting the recommended route. For links where the current traffic data is registered instead of the traffic information statistics, the link cost is multiplied by a predetermined error rate (for example, 1%) set lower than the traffic information statistics. The error is calculated. In addition, for a link where both the traffic information statistical value and the current traffic data are not registered or an unprovided link, a predetermined error rate (for example, 15%) set higher than the traffic information statistical value is added to the cost of the link. Multiply to calculate the link error. Next, the sum of the error of the cost of each link is calculated, and this is used as the estimation error of the expected travel time and the expected arrival time. Further, the ratio of the estimated error to the estimated travel time (error rate) is obtained, and the reliability of the estimated travel time and the estimated arrival time is determined according to the value. For example, the reliability is determined as “high” if the ratio is less than 5%, “medium” if it is less than 10%, and “low” if it is 10% or more.

  (Processing for determining the traffic congestion level) Next, processing for determining the traffic congestion level will be described.

  The route search unit 42 determines the congestion level display section of the recommended route and the congestion level of each display section. In the present embodiment, the recommended route is divided into a plurality of sections (congestion level display sections), and the congestion level can be displayed on the display 2 in units of sections.

  This process is performed as follows, for example. That is, with reference to the congestion level included in the traffic information of each link constituting the recommended route, when adjacent links have the same congestion level, both links are assigned to the same congestion level display section. Then, the section is set to the same traffic congestion level.

  Alternatively, refer to the moving speed included in the traffic information of each link constituting the recommended route or the average moving speed obtained from the travel time and the link length included in the link data, and the moving speed of each adjacent link. If the average value belongs to the same movement speed zone among a plurality of preset movement speed zones, and the road type and the speed limit included in the link data of each of the adjacent links are the same, Each of the adjacent links is assigned to the same congestion level display section. Then, the section is set to a traffic congestion level according to the combination of the moving speed zone and the road type, or the ratio between the moving speed zone and the speed limit.

  Alternatively, the recommended route is divided for each of a plurality of links, and each section obtained as a result is set as a congestion level display section. For each congestion level display section, the average value of the moving speed included in the traffic information of the plurality of links included in the section, or the average value of the travel time and the link included in the link data of the plurality of links The average value of the moving speed obtained from the total length is obtained. In addition, an average value of the speed limits included in the link data of the plurality of links is obtained. Then, for each congestion level display section, the congestion level of the section is set to a congestion level corresponding to the average value of the moving speed and the ratio of the limit speed.

  A link that does not have traffic information on the degree of traffic congestion is handled as a traffic congestion level display section with an unknown traffic congestion level.

  (Display Process) Next, the display process of the information obtained as described above will be described.

  If the estimated travel time / estimated arrival time, reliability / estimation error, and the congestion level display section / congestion level of each section are determined as described above, the display 2 displays these pieces of information ( S105). Specifically, the menu display processing unit 50 displays a graph on the display 2 via the graphics processing unit 51 so that the estimated travel time / expected arrival time, and the congestion level display section / the congestion level of each section can be known. To do. In addition, the reliability / estimation error of the expected travel time and the information source of the traffic information used for calculating the expected travel time / expected arrival time are also displayed.

  FIG. 19 shows an example of the display of such information. In this example, an estimated travel time and the like when departing at the current time (9 o'clock) is displayed. The length of the bar graph 804 is proportional to the expected travel time 806. Further, the graph 804 includes at least one traffic level display section indicating the traffic level 805, and the length of the display section is also proportional to the travel time of the section. The user can determine the congestion status of the route X for each departure time candidate by confirming the ratio shown in the graph of the congestion level display section with a high congestion level. Further, the reliability (estimated error) 807 of the estimated travel time (expected arrival time) is displayed in association with the estimated travel time (expected arrival time) 806, and the user uses the route X, It is possible to confirm how much error may occur. Further, an information source 808 of traffic information used for calculating the estimated travel time (expected arrival time) is displayed in association with the estimated travel time (expected arrival time) 806. The user can roughly determine the reliability of the estimated travel time (expected arrival time) 806 by referring to the information source 808.

  Further, as shown in FIG. 20, a map may be displayed. In FIG. 20, the recommended route 905 between the departure point 903 and the destination 904 is displayed on the map 909 so that the traffic level 906 in each traffic level display section can be identified. In FIG. 15, reference numeral 901 denotes a departure time, reference numeral 907 denotes an expected travel time (predicted arrival time) of the destination, reference numeral 908 denotes a reliability (estimated error) of the expected travel time (expected arrival time) 907, Reference numeral 911 denotes an information source of traffic information used for calculating the estimated travel time (expected arrival time) 907. For each traffic level display section, the estimated arrival time (estimated arrival time at the end node of the last link constituting the traffic level display section immediately before the traffic level display section) that reaches the traffic level display section Alternatively, it may be displayed in accordance with the start position of the congestion level display section on the map. In addition, for each congestion level display section, it may be displayed so that it can be distinguished from traffic information statistical values and current traffic data.

  The embodiment of the present invention has been described above.

  According to the present embodiment, with the above configuration, the navigation apparatus can be efficiently processed with high accuracy by efficiently obtaining and using the current traffic information in consideration of the nature of the current traffic information.

  In addition, when traffic data is received, the version of the map data held by the navigation device itself is notified in advance to the traffic data distribution source, so even if the old version of map data is held, the old version It is possible to efficiently receive traffic data expressed so as to match a link in the map data.

  In addition, by receiving unprovided link interpolation information and using the information for calculating the travel time of the unprovided link, it is possible to perform a route search including the unprovided link, and to perform a highly accurate recommended route search.

  In addition, since the route search is automatically started using the latest current traffic data when the ignition is turned on, an in-vehicle navigation device that is convenient for the user is provided.

  In the above embodiment, the rough current traffic data and weather information are obtained using FM multiplex broadcast signals, beacon signals, and communication networks. However, the present invention is not limited to this. For example, the current traffic data and weather information may be obtained by digital terrestrial broadcasting or satellite digital broadcasting.

  In the above embodiment, an example in which the present invention is applied to a vehicle-mounted navigation device has been described. However, the present invention can also be applied to a navigation device other than a vehicle-mounted navigation device.

FIG. 1 is a schematic configuration diagram of a navigation system to which an embodiment of the present invention is applied. FIG. 2 is a diagram illustrating a configuration example of data stored in the database of the traffic information distribution center 2000. FIG. 3 is a schematic configuration diagram of the in-vehicle navigation device 1000. FIG. 4 is a diagram illustrating a configuration example of map data stored in the map / statistical traffic data storage device 3. FIG. 5 is a diagram illustrating a configuration example of statistical traffic data stored in the map / statistical traffic data storage device 3. FIG. 6 is a diagram illustrating a configuration example of the second conversion table for specifying the day type from the date. FIG. 7 is a diagram illustrating a hardware configuration of the arithmetic processing unit 1. FIG. 8 is a diagram illustrating a functional configuration of the arithmetic processing unit 1. FIG. 9 is a flowchart showing an outline of the operation of the in-vehicle navigation device 1000. FIG. 10 is a flowchart for explaining the outline of the route search processing. FIG. 11 is a flowchart for explaining the timing of starting the route search. FIG. 12 is a flowchart for explaining the timing of starting the route search. FIG. 13 is a flowchart for explaining an example of the flow of route search processing. FIG. 14 is a flowchart for explaining the current traffic data update operation. FIG. 15 is a diagram illustrating a state of information exchange between the network communication unit and the traffic information distribution center. FIG. 16 is a flowchart for explaining the process (route search process A) in S103 of FIG. FIG. 17 is a flowchart for explaining the process (route search process B) in S104 of FIG. FIG. 18 is a flowchart for explaining the processing (cost calculation of each candidate link) in S10420 of FIG. FIG. 19 is a diagram showing a display example (bar graph) of recommended routes. FIG. 20 is a diagram illustrating a display example (map display) of a recommended route.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Arithmetic processing part, 2 ... Display, 3 ... Map / statistical traffic data storage device, 4 ... Voice input / output device, 5 ... Input device, 6 ... Wheel speed sensor, 7 ... Geomagnetic sensor, 8 ... Gyro, 9 ... GPS Receiver 10, network connection device 11, in-vehicle LAN device 12 FM multiplex broadcast reception device 13 beacon reception device 21 CPU 22 22 RAM 23 ROM 24 24 DMA controller 25 26 ... VRAM, 27 ... color palette, 28 ... A / D converter, 29 ... SCI, 30 ... PIO, 31 ... counter, 41 ... user operation analysis unit, 42 ... route search unit 42 ... route / present traffic data storage unit , 44 ... Route guidance section, 45 ... Map display processing section, 46 ... Current position calculation section, 47 ... Map match processing section, 48 ... Data reading section, 49 ... Trajectory storage section, 50 ... Menu Display processing unit, 51 ... Graphics processing unit, 53 ... Unprovided link interpolation information storage unit, 55 ... Network communication unit

Claims (15)

A route search method for a navigation device having a current location detection function,
The navigation device
Map data including the link data of each link constituting the road on the map,
A storage device for storing the version information of the map data;
A departure / destination setting step for setting a departure point and a destination,
Transmitting version information of the map data to a traffic information distribution center for distributing traffic information;
Current traffic data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function, and present traffic data expressed so as to conform to the version of the map data. The current data acquisition step to obtain from the distribution center;
The map data;
Using the current status data obtained in the current status data acquisition step,
A route search step for searching for a recommended route between the departure place and the destination;
A route search method for a navigation device, characterized in that: A route search method for a navigation device having a current location detection function,
The navigation device
A storage device for storing map data including link data of each link constituting the road on the map;
A departure / destination setting step for setting a departure point and a destination,
Current status data obtaining step for obtaining current status data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function;
An unprovided link interpolation information acquisition step for receiving interpolation information used when calculating a route search cost for an unprovided link for which no current data is provided;
The map data;
Current status data obtained in the current status data acquisition step;
Using the interpolation information obtained in the unprovided link interpolation information obtaining step,
A route search step for searching for a recommended route between the departure place and the destination;
A route search method for a navigation device, characterized in that: A route search method for a navigation device according to claim 1 or 2,
The storage device further stores, for each link, statistical data determined from statistical values of traffic information collected in the past,
The statistical data is classified for each traffic information collection condition that is a basis for defining the statistical data,
The route search step further includes:
Using the statistical data of the collection conditions corresponding to the date and time and the situation at the time of passage of each route constituting link constituting the route between the starting point and the destination,
A route search method for a navigation apparatus, wherein a recommended route between the departure place and the destination is searched. A route search method for a navigation device having a current location detection function,
The navigation device
Map data including the link data of each link constituting the road on the map,
For each of the links, it comprises a storage device for storing statistical data determined from statistical values of traffic information collected in the past,
The statistical data is classified for each traffic information collection condition that is a basis for defining the statistical data,
A departure / destination setting step for setting a departure point and a destination,
The map data;
Using the statistical data of the collection conditions corresponding to the date and time at the time of passage of each route constituting link constituting the route between the starting point and the destination,
Performing a route search step for searching a recommended route between the departure place and the destination;
The route search method of the navigation device, wherein the route search step performs a reroute search when a guidance route is set when the ignition is ON. A navigation device route search method according to claim 4,
The route search method of a navigation device, wherein the route search step is performed when a route searched using the statistical data is set as a guide route when the ignition is ON. A navigation device route search method according to claim 4 or 5,
The route search method for a navigation device, wherein the route search step suppresses activation of re-route search processing when the time from ignition OFF to ON is equal to or shorter than a predetermined time. It is the route search method of the navigation apparatus as described in any one of Claims 4-6,
Further, a current data acquisition step is performed for obtaining current data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function,
The route search step further includes:
A route search method for a navigation device, wherein a recommended route between the departure place and the destination is searched using the current state data obtained in the current state data obtaining step. A route search method for a navigation device having a current location detection function,
The navigation device
Map data including the link data of each link constituting the road on the map,
For each link, a storage device for storing statistical data determined from statistical values of traffic information collected in the past is provided.
A departure / destination setting step for setting a departure point and a destination,
Current status data obtaining step for obtaining current status data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function;
If the current data acquisition step for the given link has not been completed by the current data acquisition step,
The map data;
Using the statistical data of the collection conditions corresponding to the date and time at the time of passage of each route constituting link constituting the route between the starting point and the destination,
Performing a route search step for searching a recommended route between the departure place and the destination;
If the current status data acquisition step completes the acquisition of current status data for a given link,
The map data;
Statistical data of collection conditions corresponding to the date and time and the situation at the time of passage of each route constituting link constituting the route between the departure point and the destination;
Using the current status data obtained in the current status data acquisition step,
A route search step for searching for a recommended route between the departure place and the destination,
A navigation device route search method characterized by the above. A navigation device with a current location detection function,
Map data including the link data of each link constituting the road on the map,
A storage device for storing version information of the map data;
A departure / destination setting means for setting a departure point and a destination,
Means for transmitting the version information of the map data to a traffic information distribution center for distributing traffic information;
Current traffic data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function, and present traffic data expressed so as to conform to the version of the map data. Current status data acquisition means obtained from the distribution center,
The map data;
Using the current status data obtained by the current status data obtaining means,
A route search means for searching for a recommended route between the departure place and the destination;
A navigation device comprising: A navigation device with a current location detection function,
A storage device for storing map data including link data of each link constituting a road on the map;
A departure / destination setting means for setting a departure point and a destination,
Current status data obtaining means for obtaining current status data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function;
Non-provided link interpolation information obtaining means for receiving interpolation information used when determining the cost of route search for an unprovided link for which travel time or moving speed is not provided;
The map data;
Current status data obtained by the current status data obtaining means,
Using the interpolation information obtained in the unprovided link interpolation information obtaining step,
A route search means for searching for a recommended route between the departure place and the destination;
A navigation device comprising: A navigation device,
Map data including the link data of each link constituting the road on the map,
For each of the links, it comprises a storage device for storing statistical data determined from statistical values of traffic information collected in the past,
The statistical data is classified for each traffic information collection condition that is a basis for defining the statistical data,
The navigation device
A departure / destination setting means for setting a departure point and a destination,
The map data;
Current status data obtained by the current status data obtaining means,
Using the statistical data of the collection conditions corresponding to the date and time when passing each of the route constituting links constituting the route between the starting point and the destination, and the situation,
Route search means for searching for a recommended route between the starting point and the destination,
The route searching means has a function of performing a re-route search when a guidance route is set when the ignition is ON. A navigation device with a current location detection function,
Map data including the link data of each link constituting the road on the map,
For each link, a storage device for storing statistical data determined from statistical values of traffic information collected in the past is provided.
A departure / destination setting means for setting a departure point and a destination,
Current status data obtaining means for obtaining current status data determined from current traffic information of each link existing in the surrounding area of the current location detected by the current location detection function;
If the current data acquisition means has not yet completed the acquisition of current data for a given link,
The map data;
Using the statistical data of the collection conditions corresponding to the date and time at the time of passage of each route constituting link constituting the route between the starting point and the destination,
Search for a recommended route between the starting point and the destination,
When the current status data acquisition means has completed the acquisition of current status data for a given link,
The map data;
Statistical data of collection conditions corresponding to the date and time and the situation at the time of passage of each route constituting link constituting the route between the departure point and the destination;
Using the current status data obtained in the current status data acquisition step,
A route search method for a navigation device, having a function of searching for a recommended route between the departure point and the destination. A route search method performed by a system having a traffic information distribution center for distributing traffic information and a navigation device for receiving traffic information from the traffic information distribution center,
The navigation device performs a step of setting a starting point and a destination,
The navigation device performs a current location detection step of detecting a current location,
The navigation device performs a step of transmitting information relating to the current location detected in the current location detecting step and information relating to a version of map data stored in its own storage device to the traffic information center,
The traffic information distribution center performs a step of receiving information on the current location and information on a version of the map data transmitted from the navigation device;
Current status data determined by the traffic information distribution center based on current traffic information around the navigation device specified from information related to the current location of the navigation device, and expressed in conformity with the version of the map data Sending to the navigation device,
The navigation device performs a current data acquisition step of receiving the current data transmitted from the traffic information distribution center,
The navigation device is
The map data stored in the storage device;
Using the current status data obtained in the current status data acquisition step,
Performing a route search step of searching for a recommended route between the departure place and the destination;
A route search method characterized by that. A route search method performed by a system having a traffic information distribution center for distributing traffic information and a navigation device for receiving traffic information from the traffic information distribution center,
The traffic information distribution center is
Current status data determined from current traffic information of each link existing in the surrounding area of the navigation device;
For the unprovided link for which travel time or moving speed is not provided, the step of transmitting interpolation information used when determining the cost of route search to the navigation device is performed,
The navigation device is
Steps to set the starting and destination points,
A current status data obtaining step for receiving the current status data from the traffic information distribution center;
Uninterrupted link interpolation information acquisition step,
The map data;
Current status data obtained in the current status data acquisition step;
Using the interpolation information obtained in the unprovided link interpolation information obtaining step,
A route search step for searching for a recommended route between the starting point and the destination,
A route search method characterized by that. A route search method for a navigation device according to any one of claims 1 to 8,
The navigation device route search method, wherein the current status data obtaining step includes a step of receiving traffic information from a beacon.

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