JP2006047246A - Route searching method for navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To search a route while taking times required for right and left turns properly into account. <P>SOLUTION: This navigation system stores a cost in each branch point. The costs in the branch points are found by statistical processing, based on traffic information collected in the past, and are classified a collection condition by a collection condition. When searching the route, the route is searched to make total cost minimum, using the cost in the branch point of the collection condition corresponding to a situation when passing the branch point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  Patent Document 1 describes a navigation device that performs a route search in consideration of the time required for turning left and right. In the technique of Patent Document 1, a uniformly required time for turning right and left is added to the link travel time, and a route that minimizes the total travel time is searched.

JP 2002-162243 A

  However, the time required for turning left and right is not actually uniform. The time required for turning left and right varies depending on the type of intersection and time zone. Therefore, with the technique of Patent Document 1, it is not always possible to perform a route search that appropriately considers the time required for turning left and right.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to search for a recommended route in consideration of the time required for turning right and left more accurately.

  In order to solve the above-described problem, the navigation device route search method of the present invention stores the cost at each branch point in the storage device of the navigation device. Then, in the route search, the route with the minimum cost is searched in consideration of the cost for each branch point.

  For example, the navigation device has a storage device that stores the link cost of each link constituting the road on the map and the link connection cost that is the cost at the branch point. The link connection cost is stored for each branch point in correspondence with the situation when the branch point passes. Then, the navigation device searches for a route having the minimum total cost by using the link cost and the inter-link connection cost corresponding to the situation when passing through the branch point.

  Specifically, the navigation device is obtained by statistical processing from the link cost of each link constituting the road on the map and the traffic information collected in the past, and is classified for each collection condition of the traffic information. A storage device is provided for storing a link connection cost, which is a cost at a road branch point. Then, the navigation device searches for a route having the minimum total cost by using the link cost and the link connection cost of the collection conditions corresponding to the situation at the time of passing through the branch point.

  Further, the navigation device may obtain a congestion degree corresponding to the branch direction by using the link connection cost of the collection condition corresponding to the situation when the branch point passes, and display the obtained congestion degree.

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

  FIG. 1 is a schematic configuration diagram of an in-vehicle navigation device 1000 according to an embodiment of the present invention. As shown in the figure, the in-vehicle navigation device 1000 of the present embodiment includes an arithmetic processing unit 1, a display 2, a data storage device 3, a voice input / output device 4, an input device 5, a wheel speed sensor 6, It has a geomagnetic sensor 7, a gyro sensor 8, a GPS (Global Positioning System) receiver 9, an in-vehicle LAN device 11, an FM multiplex broadcast receiver 12, and a beacon receiver 13.

  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. Further, map data necessary for display is read out from the data storage device 3 based on the obtained current location information. 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. Further, using the map data and statistical traffic data stored in the data storage device 3, an optimum route (recommended route) connecting the destination instructed by the user and the current location (departure location) is searched. Further, 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. The display 2 is composed of 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 data storage device 3 includes a storage medium such as a CD-ROM, DVD-ROM, HDD, or IC card. This storage medium stores map data 310, statistical traffic data 320, and the like.

  FIG. 2 is a diagram showing the configuration of the map data 310. The map data 310 includes link data 312 of each link constituting a road included in the mesh area for each mesh area identification code (mesh ID) 311 obtained by dividing the area on the map.

  The link data 312 includes, for each 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 link length. Link length information 3124, link travel time information 3125, and link ID (connection link ID) 3126 of the link connected to each of the two nodes. 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 link travel time 3125 is obtained from the map information such as the link length and the speed limit, and is different from the travel time included in the statistical traffic data 320 obtained by statistical processing from past traffic information described later. The link travel time information 3125 can be omitted from the data. In that case, the travel time of the link may be generated from the road type 3123 and the link length information 3124.

  The link data 312 also includes information on the presence of a lane such as a right turn lane, a left turn lane, and a straight lane, its arrangement, and the like.

  The map data 310 also includes information (name, type, coordinate information, etc.) of map components other than roads included in the corresponding mesh area.

  FIG. 3 is a diagram illustrating a configuration of the statistical traffic data 320. The statistical traffic data 320 includes traffic information statistical data (statistic values of traffic information collected in the past) 322 of each link constituting a road included in the mesh region for each mesh ID 321 of the mesh region. The mesh ID 321 is the same as the mesh ID 311 of the map data 310. The traffic information statistical data 322 includes traffic information statistical values 3224 corresponding to the collection conditions 3221 and 3222 and the link ID 3223. The link ID 3223 of each link is the same as the link ID 3121 of the map data 310.

  The collection conditions include a day type 3221 and a weather type 3222. The day type 3221 is determined for each unit in which the traffic information statistical value 3224 indicates a different tendency. As the type of day 3221, weekdays before holidays, “weekdays (before holidays)”, weekdays after holidays, “weekdays (after holidays)”, weekdays before special days such as Bon, New Year, etc. Weekdays at the end 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 special days)” "Holidays (general)" etc.

  The weather type 3222 of the collection condition is determined for each unit in which the traffic information statistical value 3224 shows a different tendency. Examples of the weather type 3222 include “clear / cloudy”, “rain”, “heavy rain”, “snow”, “heavy snow”, and the like.

  The traffic information statistical value 3224 includes link travel time 3225 and connection travel time information 3326 for each time zone obtained by statistical processing. The connection travel time information 3226 includes a travel time required to connect from the current link (link 3323) to the next link. For example, in a crossroad 711 as shown in FIG. 10, the time required to pass the intersection may differ depending on whether the intersection approach lane is a right turn lane 714, a left turn lane 712, or a straight lane 713. In the case of left-hand traffic as in Japan, the right turn lane tends to be congested. FIG. 4 shows a configuration example of connection travel time information 3226 in the case of a crossroad. As illustrated, the connection travel time information 3226 includes a next link ID 32262 and a connection travel time 32263 for each lane 32261. Thus, the connection travel time 32263 is provided in consideration that the travel time differs depending on the intersection approach lane corresponding to the branch direction. For links that do not have multiple lanes (or right / left turn lanes), the traffic information statistics value 3224 may not have the connection travel time information 3226.

  These traffic information statistical values are obtained by performing statistical processing based on a plurality of traffic information collected in the past.

  As described above, the traffic information statistical value 3224 is classified according to the traffic information collection conditions (the day type 3221 and the weather type 3222 when the base traffic information is collected) and the target link 3223. ing. That is, if the day type 3221, the weather type 3222, the link ID 3223, and the time zone are determined, the link travel time 3325 obtained by the statistical processing can be extracted. Further, the time taken to connect from the target link to the next link (in other words, the time taken to turn right or left) can be extracted as the connection travel time 33263.

  The data storage device 3 further stores a date conversion table that is a conversion table for specifying the type of date registered in the date type list 3221 from the date of the month.

  FIG. 5 is a diagram illustrating a configuration example of a date 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 date conversion table, the type of day can be easily specified from the date.

  Returning to FIG. 1, 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. Also, a process of recognizing the voice uttered by the user and transferring the contents to the arithmetic processing unit 1 is performed.

  The input device 5 is a unit that receives instructions from the user. The input device 5 includes a hard 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 by the in-vehicle navigation device 1000 to detect the current location (own vehicle position). 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 to thereby determine the current position, travel speed, and travel of the mobile body. Measure orientation.

  The in-vehicle LAN device 11 receives various information of the vehicle on which the in-vehicle navigation device 1000 is mounted, such as door opening / closing information, light lighting state information, engine status, failure diagnosis result, and the like.

  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 as FM multiplex broadcast signals.

  The beacon receiving device 13 receives current traffic data including the link travel time sent from the beacon.

  FIG. 6 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 stores a CPU (Central Processing Unit) 21 that executes various processing such as numerical calculation and control of each device, and map data, statistical traffic data, arithmetic data, and the like read from the data storage device 3. A RAM (Random Access Memory) 22, a ROM (Read Only Memory) 23 for storing programs and data, a DMA (Direct Memory Access) 24 for transferring data between the memories and between the memory and each device, and graphics A drawing controller 25 that executes image drawing and performs display control, a video random access memory (VRAM) 26 that stores graphics image data, a color palette 27 that converts image data into RGB signals, and analog signals into digital signals A / D converter 28 for conversion, and S for converting the serial signal into a parallel signal synchronized with the bus Has a I (Serial Communication Interface) 29, a PIO (Parallel Input / Output) 30 put on the bus to synchronize the parallel signals to the bus, a counter 31 for integrating a pulse signal.

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

  As illustrated, the arithmetic processing unit 1 includes a user operation analysis unit 41, a route search unit 42, a route guidance unit 44, a current position calculation unit 46, and a display processing unit 45.

  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). Further, by performing map matching processing using the calculation result, the current location is matched with the road (link) having the highest shape correlation.

  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 display processing unit 45 is requested to display a map on the display 2 in order to set a destination. Further, it requests the route search unit 42 to calculate a route from the current location (departure location) to the destination.

  The route search unit 42 uses a Dijkstra method or the like to search for a route that minimizes the cost (for example, travel time) of a route connecting two designated points (current location, destination).

  The route guidance unit 44 performs route guidance using the route searched by the route search unit 42. For example, the information on the route is compared with the information on the current location, and the voice input / output device 4 is used to inform the user by voice whether the vehicle should go straight before passing an intersection or the like. Further, the route guiding unit 44 displays the direction to travel on the map displayed on the display 2 and notifies the user of the recommended route.

  The display processing unit 45 receives the map data in the area required to be displayed on the display 2 from the data storage device 3, and at the specified scale and drawing method, the road, other map components, the current location, the destination Then, a map drawing command is generated so as to draw a mark such as an arrow for the guide route. Further, in response to a command output from the user operation analysis unit 41, statistical traffic data required to be displayed on the display 2 is received from the data storage device 3, and traffic on each road is displayed on the map being displayed on the display 2. A map drawing command is generated so that information is displayed in an overlapping manner. Then, the generated command is transmitted to the display 2.

  [Description of Operation] Next, the operation of the vehicle-mounted navigation device 1000 will be described. FIG. 8 is a flowchart showing an outline of the operation of the in-vehicle navigation device 1000 of the present embodiment.

  This flow starts when the user operation analysis unit 41 receives a search request for a recommended route from the user via the voice input / output device 4 or the input device 5.

  First, the user operation analysis unit 41 sets a departure place. The user operation analysis unit 41 normally sets the current location obtained by the current position calculation unit 46 as a departure location. The user operation analysis unit 41 also sets a destination based on a user instruction. For example, the user operation analysis unit 41 reads a map constituent registered in the map data from the data storage device 3. The user operation analysis unit 41 displays these map components on the display 2 via the display processing unit 45. The user operation analysis unit 41 causes the user to select a destination from the information of the displayed map constituent via the input device 5. The user operation analysis unit 41 also sets a departure time. 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) or the like (S102).

  Next, the route search unit 42 specifies the mesh ID of each mesh region included in the route search region including the departure point and the destination from the coordinates of the current position. The route search unit 42 also obtains each link data 312 registered in each map data 310 having the specified mesh ID from the data storage device 3. The route search unit 42 also reads the date conversion table from the data storage device 3. The route search unit 42 also specifies the type of departure date using the date conversion table. In addition, when the date of departure is not registered in the date conversion table, the route search unit 42 specifies the type of day from the date by calculation logic. The process of specifying the type of day corresponding to the departure date may be executed by software incorporated in the vehicle-mounted navigation device. In this way, even when the date range registered in the date conversion table is exceeded, the processing can be continued (S104).

  Next, the route search unit 42 uses each link data 312 obtained in S104, and uses the link starting from the end node of the extracted link extracted from the heap table in S118, which will be described later, as a candidate constituting a recommended route. Elect as a link. However, when the processing in S118 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 extraction link end node as a start node as a candidate link, the departure place Is selected as a candidate link (S106).

  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 travel time to the extraction link registered in the heap table to the departure time. At this time, not only the link travel time but also the connection travel time between links is added to obtain the total travel time. In addition, the route search unit 42 identifies the mesh ID of the mesh region where the end node is located from the coordinates of the end node of the extraction link. However, when the process in S118 is not performed, that is, in the initial stage where no link is 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. Get weather information. 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 (S108).

  Next, the route search unit 42 accesses the statistical traffic data 320 having the mesh ID specified in S <b> 104 stored in the data storage device 3. Then, using this statistical traffic data 320, for each candidate link, the traffic information statistical value of the time of interest and the weather specified by the type of day specified in S104 and the weather information acquired in S106 are displayed. The traffic information statistical value 3224 associated with the type is obtained. Then, the link travel time 3225 included in the traffic information statistical value 3224 is obtained.

  Further, the route search unit 42 associates the extracted link with the traffic information statistical value of the time period of interest and the type of weather specified by the type of day specified in S104 and the weather information acquired in S106. Obtained traffic information statistics value 3224. Then, the connection travel time information 3226 included in the traffic information statistical value 3224 is referred to, and the connection travel time 32263 to each candidate link (next link) is obtained.

  In this way, the route search unit 42 obtains the link travel time and the connection travel time for each candidate link (S110).

  Next, the route search unit 42 calculates the total cost from the departure point to the end node of the candidate link. Specifically, the cost (link travel time) and connection cost (connection travel time) of the candidate link obtained in S110 are added to the total cost up to the extraction link registered in the heap table. Then, the addition result is set as the total cost up to 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 S110 is set as the total cost up to 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 (S114).

  Next, the route search unit 42 checks whether there is a destination link among the links newly added to the heap table (S116). If it is determined that there is no destination link (No in S116), 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 unextracted link that is located. For example, the candidate link (unextracted link) with the lowest total cost is extracted from the heap table (S118). Then, the process returns to S106.

  On the other hand, when it is determined that there is a destination link (Yes in S116), 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.

  The route search process applicable to the present invention is not limited to the above. If the present invention can be implemented within the scope of the gist, other route search methods can be adopted. For example, a route search method in which all routes from the starting point to the destination included in the assumed mesh area are searched with the brute force method using the Dijkstra method, etc., and then the route with the shortest cost is searched for among the routes. May be adopted.

  The processing for searching for a recommended route has been described above.

  When the recommended route is searched, the route search unit 42 instructs the route guide unit 44 to perform route guidance using the searched route. In response to this, the route guidance unit 44 starts route guidance. The route guiding unit 44 performs guidance by displaying a recommended route on the display 2.

  FIG. 9 is an example of the display screen 701 of the display 2 during route guidance. As shown in the figure, the route guiding unit 44 displays a map 702 on the display screen 701. Then, the recommended route 704 is displayed together with the current position 703. The route guiding unit 44 also displays a degree of traffic jam (traffic jam level) 706. The degree of congestion 706 can be obtained from the traffic information statistical value 3324. Specifically, the travel speed is obtained from a value obtained by dividing the link travel time 3325 by the link length 3124, and the degree of congestion is obtained according to the magnitude of the travel speed. The level of the degree of traffic congestion (for example, “high”, “medium”, “low”) is determined in advance according to the moving speed.

  The route guiding unit 44 also displays a traffic jam degree 708 at a branch point 707 such as an intersection. The traffic congestion degree 708 at the branch point can be obtained from the connection travel time information 3226 of the traffic information statistical value 3324. Specifically, the degree of traffic congestion is obtained according to the connection travel time 33263. The level of traffic congestion level (for example, “high”, “medium”, “low”) is determined in advance according to the length of the connection travel time.

  In addition, the route guiding unit 44 may display only those related to the recommended route when displaying the degree of congestion. In this way, information not related to the recommended route is not displayed, and the display screen can be prevented from becoming complicated.

  In addition, when the degree of congestion differs depending on the lane before branching at an intersection or the like, only the degree of congestion on the lane on the recommended route may be displayed. In the example of FIG. 9, the recommended route 704 turns right at the intersection 707. Therefore, only the traffic congestion degree 708 in the right lane is displayed on the display screen 701.

  The route guiding unit 44 may also enlarge and display the state of the branch point. FIG. 10 is a diagram showing an enlarged display of the state of the intersection. In the example of FIG. 10, the route guidance unit 44 enlarges and displays an intersection 711 having a left turn lane 712, a straight ahead lane 713, and a right turn lane 714. In addition, the route guidance unit 44 displays a recommended route 715 that turns right at the intersection 711. Further, the degree of congestion 721 to 723 is displayed for each lane. In the example of FIG. 9, the congestion degree of all lanes is displayed, but the congestion degree of only the lane related to the recommended route (right turn lane 714 in the example of FIG. 10) may be displayed.

  Further, the route guiding unit 44 may determine whether or not to display the congestion degree for each lane (for each branch direction) according to an enlarged scale of the map display. For example, the route guidance unit 44 displays the degree of congestion for each lane when the scale of the map display reaches the point where the branch direction can be displayed.

  Further, the route guidance unit 44 may display only one traffic congestion level when the traffic congestion levels are the same in a plurality of lanes.

  In addition, the congestion level may be displayed in characters, or sections of different congestion levels may be displayed in different manners by attaching a specific color to the link.

  The embodiment of the present invention has been described above.

  According to the above-described embodiment, the recommended route can be searched in consideration of the time required for turning left and right at each branch point.

  Further, in the route search, the travel time required for turning left and right at the branch point is not uniformly determined, but travel time obtained from past traffic information is used. Therefore, the travel time from the departure place to the destination can be obtained more accurately.

  The above embodiment can be variously modified within the scope of the gist of the present invention.

  For example, in the above embodiment, the vehicle-mounted navigation device 1000 holds the statistical traffic data 320 in the data storage device 3. The present invention is not limited to this. You may make it receive from the center which distributes the traffic information and prediction information similar to the statistical traffic data 320. FIG.

  The outline of a structure of the navigation system in the case of FIG. 11 is shown. As shown in the figure, the navigation system 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, an FM multiplex broadcast station 5000, traffic information A management center 6000 and a weather information management center 7000 are included.

  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 and the FM multiplex broadcasting station 5000.

  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 broadcasts the traffic information of each area distributed from the traffic information management center 6000. 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 traffic information distribution center 2000 stores statistical traffic data in its database. The configuration of the statistical traffic data can be the same as the configuration of the statistical traffic data 320 shown in FIG.

  The in-vehicle navigation device 1000 is configured in the same manner as the configuration shown in FIG. 1, but further includes a communication device that exchanges information with the traffic information distribution center 2000.

  In the configuration as described above, the route search unit 42 of the in-vehicle navigation device 1000 accesses the traffic information distribution center 2000 via the communication device and downloads (receives) traffic data. At this time, the traffic information distribution center 1000 may be requested to transmit only traffic data used for route search (for example, statistical traffic data of a mesh region including a route from the departure point to the destination). Good. Then, the route search unit 42 searches for a recommended route from the departure point to the destination using the received statistical traffic data. The flow of the search process can be performed similarly to the flow shown in FIG.

  According to such an embodiment, the in-vehicle navigation device 1000 itself does not need to hold statistical traffic data. Even when the statistical traffic data is updated, the latest traffic data can be easily acquired by accessing the traffic information distribution center 2000.

  The traffic information distribution center 1000 may transmit to the in-vehicle navigation device 1000 only the connection travel time relating to the branch in which the difference (or ratio) of the connection travel time for each branch direction is a predetermined value or more. For example, only the connection travel time of a lane whose connection travel time difference is equal to or greater than a predetermined value is transmitted to the in-vehicle navigation device 1000 based on the connection travel time to the next link of the straight lane. In this way, the amount of information communication can be reduced.

  Moreover, in the said embodiment, you may make it the vehicle by which the vehicle-mounted navigation apparatus 1000 is mounted function as a probe car which collects traffic information. For example, the link travel time and the connection travel time calculated by actually traveling are transmitted to the traffic information distribution center 200. When the actual value and the value included in the statistical traffic data are different (for example, when the difference or ratio is equal to or greater than a predetermined value), the data may be transmitted to the traffic information distribution line 2000. For example, the link travel time and connection travel time included in the statistical traffic data held by the in-vehicle navigation device 1000 itself or the statistical traffic data received from the traffic information distribution center 2000 differ from the actual link travel time and connection travel time. In this case, the actual link travel time and connection travel time are transmitted to the traffic information distribution center 200. In this way, the vehicle on which the in-vehicle navigation device 1000 is mounted functions as a probe car. The traffic information distribution center 2000 can efficiently collect traffic information.

  FIG. 12 is a flowchart of processing of the in-vehicle navigation device 1000 according to this embodiment. This flow is performed during route guidance.

  First, the route guidance unit 44 determines whether the vehicle has moved to the next link from the output of the current position calculation unit 46 (S210). When moving to the next link (Yes in S210), the route guiding unit 44 calculates the travel time (actual travel time) from the start node of the previous link (target link) to the start node of the current link from the travel history. Calculate (S220).

  Next, the route guidance unit 44 refers to the statistical traffic data 320 and extracts the link travel time 3325 and the connection travel time 3326 corresponding to the type of day and weather type on the target link. Then, the sum of the extracted link travel time 3325 and the connection travel time 3326 is calculated. Further, a difference between the calculated sum value and the travel time actually traveled calculated in S220 is calculated. Further, it is determined whether or not the calculated difference is a predetermined value (for example, 5 minutes) or more (S230). If the difference is less than the predetermined value (No in S230), the process returns to S210 and continues.

  On the other hand, if the difference is equal to or greater than the predetermined value (Yes in S230), the route guiding unit 44 sends the actual travel time (travel time from the start node of the target link to the start node of the next link) to the traffic information distribution center 2000. Then, the data is transmitted via the communication device (S240). And it returns to S210 and continues a process. A value obtained by subtracting the link travel time 3225 of the statistical traffic data from the actual travel time may be transmitted to the traffic information distribution center 2000 as the actual connection travel time (right / left turn cost).

  The traffic information distribution center 2000 calculates the link travel time and the connection travel time of the link by statistical processing based on the actual travel time received from the in-vehicle navigation device 1000.

  According to such an embodiment, the in-vehicle navigation device 1000 functions as a probe car that collects connection travel time (right / left turn cost) between links.

  Further, since the information is transmitted to the traffic information distribution center 2000 only when the connection travel time stored in the statistical traffic data is different from the actual travel time, the amount of information communication can be reduced.

  Moreover, in the said embodiment, route search is performed using statistical traffic data. However, the present invention is not limited to this, and a route search may be performed using current traffic information. For example, when the current traffic data received from the beacon or the traffic information distribution center 2000 includes a link travel time or a connection travel time between links, a route search is performed using such information. If the current travel data does not include the link travel time or the connection travel time, interpolation is performed using the link travel time or the connection travel time included in the statistical traffic data. Specifically, the processing shown in FIG. 13 is performed in S110 of the flow of FIG.

  The route search unit 42 determines whether there is current traffic data for each candidate link (S1101). When there is no current traffic data (No in S1101), the link travel time 3325 is obtained from the statistical traffic data 320 as in the above embodiment (S1102). On the other hand, if there is current traffic data (Yes in S1101), the travel time of the candidate link of the current traffic data is obtained (S1103).

  Next, the route search unit 42 determines whether there is current traffic data for the connection travel time to each candidate link (S1104). When there is no current traffic data (No in S1104), the connection travel time 3326 is obtained from the statistical traffic data 320 as in the above embodiment (S1105). On the other hand, if there is current traffic data (Yes in S1104), the connection travel time of the current traffic data is obtained (S1106).

  When the route search unit 42 performs the processing of S1101 to S1106 for all candidate links (S1107), the route search unit 42 proceeds to S114 of FIG. 7 and continues the processing.

  According to the above flow, a route search can be performed using the obtained current traffic data with priority. Note that the current traffic data may be used for a specific range on the map (for example, around the current position), and the statistical traffic data may be used for other ranges.

  In the above embodiment, as shown in FIG. 3, the traffic information statistical value 3224 is registered in the statistical traffic data 320 for each type of collected weather. However, the statistical traffic data 320 may be obtained by omitting the weather collection condition.

  Moreover, in the said embodiment, connection travel time is stored for every link in statistical traffic data. However, the form of the data structure is not limited as long as the gist of the present invention can be achieved. For example, the connection travel time may be stored in correspondence with the branch node. Further, the connection travel time may be included in the link travel time. Then, the link travel time may be stored in the statistical traffic data for each lane of the link. Moreover, about the link with connection travel time, you may include the flag information which shows that in statistical traffic data.

  Moreover, although the example which applied this invention to the vehicle-mounted navigation apparatus was demonstrated, this invention is applicable also to navigation apparatuses other than vehicle-mounted.

FIG. 1 is a schematic configuration diagram of an in-vehicle navigation device 1000. FIG. 2 is a diagram showing a configuration of map data stored in the data storage device 3. FIG. 3 is a diagram showing the structure of statistical traffic data. FIG. 4 is a diagram illustrating a configuration of connection travel time information. FIG. 5 is a diagram showing a configuration of a date conversion table for specifying a day type from a date. FIG. 6 is a diagram illustrating a hardware configuration of the arithmetic processing unit 1. FIG. 7 is a diagram illustrating a functional configuration of the arithmetic processing unit 1. FIG. 8 is a flowchart showing an outline of the route search process of the vehicle-mounted navigation device 1000. FIG. 9 is a diagram illustrating a display example of a recommended route during route guidance. FIG. 10 is a diagram showing a display example of an enlarged intersection view during route guidance. FIG. 11 is a schematic configuration diagram of an embodiment for receiving statistical traffic data from a traffic information distribution center. FIG. 12 is a flowchart of an embodiment for causing a vehicle to function as a probe car. FIG. 13 is a flowchart of the process in S110 of FIG. 8 when a route search is performed using the current traffic data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Arithmetic processing part, 2 ... Display, 3 ... Data storage device, 4 ... Voice input / output device, 5 ... Input device, 6 ... Wheel speed sensor, 7 ... Geomagnetic sensor, 8 ... Gyro, 9 ... GPS receiver, 11 ... In-vehicle LAN device, 12 ... FM multiplex broadcast receiving device, 13 ... Beacon receiving device, 21 ... CPU, 22 ... RAM, 23 ROM, 24 DMA, 25 drawing controller, 26 VRAM, 27 color palette, 28 A / D converter, 29 SCI , 30 ... PIO, 31 ... counter, 41 ... user operation analysis unit, 42 ... route search unit, 44 ... route guidance unit, 45 ... display processing unit, 46 ... Current position calculator

Claims (19)

A navigation device route search method,
The navigation device
A storage device for storing the link cost of each link constituting the road on the map and the link connection cost that is the cost at the branch point;
The link connection cost is stored for each branch point, corresponding to the situation when the branch point passes,
The navigation device
A route search method for a navigation device, wherein a route that minimizes the total cost is searched using the link cost and an inter-link connection cost corresponding to a situation at the time of passing through a branch point. In claim 2,
A route search method for a navigation device, characterized in that the situation when passing through the branch point is any one or more of a day type, a weather, and a time zone. A navigation device route search method,
The navigation device
The link cost of each link that makes up the road on the map,
A storage device that stores link connection costs, which are costs at branch points of roads, obtained by statistical processing from traffic information collected in the past and classified for each traffic information collection condition,
A route search method for a navigation device, wherein a route that minimizes the total cost is searched using the link cost and a link connection cost of collection conditions corresponding to a situation when the vehicle passes through a branch point. A navigation device route search method,
The navigation device
The link cost of each link that makes up the road on the map,
A storage device that stores link connection costs, which are costs at branch points of roads, obtained by statistical processing from traffic information collected in the past and classified for each traffic information collection condition,
A route search method for a navigation device, wherein an arrival time at a destination is calculated using the link cost and a link connection cost of collection conditions corresponding to a situation at the time of passing through a branch point. In claim 3,
The navigation device
A route search method for a navigation device, characterized in that a congestion degree corresponding to a branching direction is obtained using a link-to-link connection cost of a collection condition corresponding to a situation when a branch point passes and the obtained congestion degree is displayed. In claim 5,
The navigation device
A route search method for a navigation device, characterized in that, when the congestion degree varies depending on the branch direction, the congestion degree is displayed for each branch direction. In claim 5,
The navigation device
A route search method for a navigation device, characterized in that any one of the traffic congestion levels is displayed for branch directions having the same traffic congestion level. In claim 5,
The navigation device
A route search method for a navigation device, characterized by displaying a degree of congestion for each intersection approaching lane corresponding to a branch direction. In claim 5,
The navigation device
A route search method for a navigation device, characterized in that, when an enlarged scale of a map display is a predetermined value or more, a congestion degree is displayed in correspondence with a branch direction. In claim 5,
The navigation device
A route search method for a navigation device, characterized by displaying a degree of traffic congestion in a lane along the searched route. A navigation device route search method,
The navigation device
The link connection cost is received from the information center that stores the link connection cost, which is the cost at the road junction,
A route search method for a navigation device, wherein a route that minimizes the total cost is searched using a connection cost between links in a collection condition corresponding to a situation when a branch point passes. In a route search method for a navigation system having an information center and a navigation device,
The information center stores an inter-link connection cost, which is a cost at a road branch point,
Between the branch directions, the link connection cost related to the branch having a difference or ratio of the connection cost between links of a predetermined value or more is transmitted to the navigation device;
The navigation device
Receive the link connection cost from the information center,
A route search method for a navigation system, characterized in that a route with a minimum total cost is searched using a link connection cost of collection conditions corresponding to a situation when a branch point passes. A processing method for a navigation device, comprising:
The navigation device
A storage device that stores link connection costs, which are costs at branch points of roads, obtained by statistical processing from traffic information collected in the past and classified for each traffic information collection condition,
When the link connection cost stored in the storage device is different from the actual one, the traffic information acquired by the actual trip is transmitted to the information center collecting the traffic information. A navigation device route search method,
The navigation device
The link cost of each link that makes up the road on the map,
A storage device that stores link connection costs, which are costs at branch points of roads, obtained by statistical processing from traffic information collected in the past and classified for each traffic information collection condition,
Get current data, including current traffic information,
A route search method for a navigation device, wherein the current state data is interpolated by a link cost and an inter-link connection cost stored in the storage device to search for a route having a minimum total cost. In claim 14,
The navigation device
For branch points where the link data is included in the current data, the link cost is used.
For a branch point that does not include an inter-link connection cost in the current data, a route that minimizes the total cost is searched using the inter-link connection cost stored in the storage device. Device route search method. In claim 14,
A route search method for a navigation device, characterized in that, for a link in a specific range on a map, a route that minimizes the total cost is searched by using an inter-link connection cost included in the current status data. A navigation device route search method,
The navigation device
Link data for each link that makes up the road on the map,
The link cost of each link obtained by statistical processing from traffic information collected in the past and classified for each traffic information collection condition,
A storage device that stores link connection costs, which are costs at branch points of roads, obtained by statistical processing from traffic information collected in the past and classified for each traffic information collection condition,
Using the link data, the link cost of the collection condition corresponding to the situation at the time of passing through the link, and the link connection cost of the collection condition corresponding to the situation at the time of passing through the branch point, the route having the minimum total cost is searched. A route search method for a navigation device, characterized in that: A navigation device,
A storage device for storing the link cost of each link constituting the road on the map and the inter-link connection cost, which is the cost at the branch point, classified into the situation at the time of passing through the branch point;
A navigation apparatus comprising: means for searching for a route having a minimum total cost by using the link cost and an inter-link connection cost corresponding to a situation at the time of passing through a branch point. In claim 18,
The storage device stores an inter-link connection cost of only a link having a right turn lane or a left turn lane.

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