JP2004301677A - Method of searching for course on navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of searching for a recommended course by using traffic information collected in the past. <P>SOLUTION: A map & statistics traffic data storage 3 has map data including link data on respective links constituting roads on a map, and statistics data including traveling time or moving speed for each time zone on the respective links determined by traffic information statistics collected in the past stored therein. An on-vehicle navigation device searches for the recommended course between a place of departure and a destination by using the map data stored in the data storage 3 and traffic information statistics values on the respective links in a mesh area corresponding to a time zone including referential arrival time to the mesh area determined by the day and hour of departure and a distance from the place of departure to the mesh area with respect to each mesh area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a navigation device, and more particularly to a route search technology and a traffic information display technology of a vehicle-mounted navigation device.
[0002]
[Prior art]
Patent Literature 1 discloses a technique in a navigation device that changes a display form of a predetermined road on a map displayed on a display in accordance with a degree of congestion. For example, when the route searched by the route search includes the predetermined road, the part of the predetermined road included in the route is determined based on traffic information collected in a past predetermined period. Display mode according to the degree of traffic congestion. Here, traffic information collected in a past predetermined period may be classified for each predetermined time zone. In this way, by changing the traffic information of the road used to determine the display mode of the road in accordance with the time, the display mode of the road can be changed according to the traffic congestion that changes in real time. .
[0003]
[Patent Document 1]
JP-A-10-82644
[0004]
[Problems to be solved by the invention]
However, the technology described in Patent Document 1 does not consider using traffic information collected in the past for route search.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to accurately search for a recommended route using traffic information collected in the past.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, in the route search method of the present invention, map data including link data of each link constituting a road on a map is stored in a storage device of the navigation device. Further, statistical data including a travel time or a moving speed for each time zone of each link determined from a statistical value of traffic information collected in the past is stored. And setting the departure time, departure location, and destination of the route to be searched in the navigation device, and using the map data and the statistical data stored in the storage device, the departure location and the destination. And a route search step of searching for a recommended route between them. Here, the route search step uses, for each of the candidate links of the links constituting the recommended route, statistical data of a time zone determined according to the departure time and the distance from the departure point to the candidate link, The cost (moving time) for searching the route of the candidate link is determined.
[0007]
As described above, by calculating the cost of each candidate link using the statistical data of the time zone determined according to the departure time and the distance from the departure place to the candidate link, the total cost (travel time) is minimized. A route can be searched with high accuracy.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is a schematic configuration diagram of a vehicle-mounted navigation device to which an embodiment of the present invention is applied.
[0010]
As shown in the figure, the on-vehicle navigation device according to the present 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, a wheel speed sensor. 6, a geomagnetic sensor 7, a gyro sensor 8, a GPS (Ground Positioning System) receiving device 9, and an in-vehicle LAN device 11.
[0011]
The arithmetic processing unit 1 is a central unit that performs various processes. For example, the current position is detected based on information output from the various sensors 6 to 8 and the GPS receiving device 9, and map data necessary for display is stored on the map / statistical traffic data storage device 3 based on the obtained current position information. Read from In addition, the read map data is developed into graphics, a mark indicating the current location is superimposed on the read map data, displayed on the display 2, or the map data and the statistical traffic data stored in the map / statistical traffic data storage device 3 are used. A search is made for an optimal route (recommended route) connecting the destination designated by the user and the departure place (for example, the current location), and the user is guided using the voice input / output device 4 and the display 2.
[0012]
The display 2 is a unit that displays the 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.
[0013]
The map / statistical traffic data storage device 3 is configured by a storage medium such as a CD-ROM, a DVD-ROM, an HDD, and an IC card. This storage medium stores map data and statistical traffic data.
[0014]
FIG. 2 is a diagram showing a configuration example of the map data stored in the map / statistical traffic data storage device 3. As shown in the figure, map data 31 is stored for each mesh area obtained by dividing the map into a plurality. The map data 31 has an identification code (mesh ID) 311 of a mesh area 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 (a start node and an end node) forming the link, road type information 3123 including the link, and a link indicating the length of the link. It has length information 3124, travel time (or moving speed) information 3125 of the link, a link ID (connection link ID) 3126 of the link connected to each of the two nodes, and the like. Here, the start node and the end node are distinguished for the two nodes constituting the link, so that the up direction and the down direction of the same road are managed as different links. In addition, the map data 31 also includes information (name, type, coordinate information, etc.) of map components other than roads included in the corresponding mesh area.
[0015]
FIG. 3 is a diagram showing a configuration example of the statistical traffic data stored in the map / statistical traffic data storage device 3. As shown in the figure, statistical traffic data 32 is stored for each of the above-described mesh areas. The statistical traffic data 32 is management data for managing the mesh ID 321 of the mesh area and the traffic information statistics (statistics of 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 31. The management data 322 includes a plurality of tables 3221 to 223 having a hierarchical structure.
[0016]
The table 3221 is a table for registering the type of day. The type of day may be determined for each unit in which the traffic information statistical value shows a different tendency. Here, as the types of days, weekdays before a holiday “weekdays (before holidays)”, weekdays after holidays “weekdays (after holidays)”, weekdays before unusual days such as Bon and New Year, “weekdays (unique days before)”, unusual days Weekdays at dawn "weekdays (after special days)", other weekdays "weekdays (general)", first days of special days "holidays (beginning of special days)", all day of special days "holidays (end of special days)", other The holiday "holiday (general)" is included.
[0017]
The table 3222 is a table for registering link IDs of links constituting roads included in the mesh area registered by the mesh ID 321, and is provided for each type of day registered in the table 3221. The link ID is the same as the link ID 3121 of the map data 31.
[0018]
The table 3223 is a table for registering traffic information statistical values for each time zone, and is provided for each link ID registered in the table 3222. The traffic information statistical value for each time zone includes a link travel time (or travel speed) specified by a plurality of traffic information from which the traffic information is based, a degree of dispersion (dispersion degree) of the link travel time (or travel speed), and Includes link congestion degree. In addition, the traffic information statistical value for each time zone is classified based on the collection conditions of the original traffic information (the type of day on which the original traffic information was 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 3223 is a link specified by the link ID of the table 3222 associated with this table 3223, and The original traffic information is traffic information collected on the day specified by the day type in the table 3221 associated with the table 3222 in which the link ID is registered.
[0019]
In addition, the traffic information statistical value includes the degree of dispersion (degree of dispersion) of the link travel time specified by the plurality of traffic information on which the traffic information is based. 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.
[0020]
The map / statistical traffic data storage device 3 has, in addition to the above-described map data and statistical traffic data, a conversion table for specifying a mesh ID of a mesh area including a point specified by the coordinate information from the coordinate information. (Referred to as a first conversion table). Further, a conversion table (referred to as a second conversion table) for specifying the type of day managed in the table 3221 from the date is stored.
[0021]
FIG. 4 is a diagram illustrating a configuration example of the second conversion table. As shown in the figure, a date 331 and a day 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 the calculation logic is executed by software incorporated in the vehicle-mounted navigation device, in order to further subdivide the classification of the day type, the vehicle-mounted navigation device may be used. You must rewrite the embedded software. In addition, the specific process of the special day such as the year-end, tray, and GW becomes complicated. In this regard, in the present embodiment, since the conversion table as shown in FIG. 4 is used, the in-vehicle navigation device can be obtained simply by replacing the DVD-ROM or the CD-ROM constituting the map / statistical traffic data storage device 3. It is possible to deal with subdivision of classification without changing the software incorporated in. In addition, by making it possible to specify the unique date from the conversion table, it is possible to deal with the processing without complicated processing.
[0022]
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 an audio signal and outputs the signal, and also performs a process of recognizing a voice uttered by the user and transferring the content to the arithmetic processing unit 1.
[0023]
The input device 5 is a unit that receives an instruction from a user, and includes a hard switch such as a scroll key and a scale change key, a joystick, and a touch panel attached on a display.
[0024]
The sensors 6 to 8 and the GPS receiving device 9 are used for detecting the current location (own vehicle position) with the on-vehicle navigation device. The wheel speed sensor 6 measures the distance from the product of the circumference of the wheel and the measured number of rotations of the wheel, and further measures the angle at which the moving body is bent from the difference between the number of rotations of the paired wheel. The geomagnetic sensor 7 detects a magnetic field held by the earth and detects a direction in which the moving object is facing. The gyro 8 includes an optical fiber gyro, a vibrating gyro, and the like, and detects an angle at which the moving body has rotated. The GPS receiver 9 receives a signal from a GPS satellite, and measures the distance between the mobile unit and the GPS satellite and the rate of change of the distance for three or more satellites to thereby determine the current position, traveling direction, and traveling direction of the mobile unit. Is measured.
[0025]
The in-vehicle LAN device 11 receives various information of the vehicle on which the on-vehicle navigation device according to the present embodiment is mounted, for example, information on opening and closing a door, information on a lighting state of a light, a condition of an engine, a result of failure diagnosis, and the like.
[0026]
FIG. 5 is a diagram illustrating a hardware configuration of the arithmetic processing unit 1.
[0027]
As shown in the drawing, the arithmetic processing unit 1 has a configuration in which each device is connected by a bus 32. The arithmetic processing unit 1 includes a CPU (Central Processing Unit) 21 that executes various processes such as numerical calculations and control of each device, and map data, statistical traffic data, and arithmetic data read from the map / statistical traffic data storage device 3. (Random Access Memory) 22 for storing data, a ROM (Read Only Memory) 23 for storing programs and data, and a DMA (Direct Memory Access) 24 for executing data transfer between memories and between the memory and each device. A graphics controller 25 for executing graphics rendering and performing display control; a VRAM (Video Random Access Memory) 26 for storing graphics image data; A color palette 27 for converting to a B signal; an A / D converter 28 for converting an analog signal to a digital signal; an SCI (Serial Communication Interface) 29 for converting a serial signal to a parallel signal synchronized with a bus; It has a PIO (Parallel Input / Output) 30 mounted on the bus in synchronization with the bus, and a counter 31 for integrating a pulse signal.
[0028]
FIG. 6 is a diagram illustrating a functional configuration of the arithmetic processing unit 1.
[0029]
As illustrated, the arithmetic processing unit 1 includes a user operation analysis unit 41, a route search unit 42, a route storage unit 43, a route guidance unit 44, a map display processing unit 45, a current position calculation unit 46, It has a map match processing unit 47, a data reading unit 48, a trajectory storage unit 49, a menu display processing unit 50, and a graphics processing unit 51.
[0030]
The current position calculation unit 46 uses the distance data and the 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, and uses the data on the time axis. Is calculated periodically from the initial position (X, Y) to the current position (X ', Y'), which is the position after the vehicle has traveled, and output to the map match processing unit 47. . Here, in order to make the relationship between the angle of rotation of the vehicle and the direction in which the vehicle advances, 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 are referred to. , The absolute azimuth of the direction in which the vehicle is traveling is estimated. When the data of the wheel speed sensor 6 and the data of the gyro 8 are integrated, errors accumulate. Therefore, the errors accumulated based on the position data S8 obtained from the GPS receiver 9 in a certain time period are calculated. The process of canceling is performed, and the information on the current location is output to the map match processing unit 47.
[0031]
The map match processing unit 47 collates the map data around the current position read by the data reading unit 48 with the travel locus stored in the locus storage unit 49 described later, and determines the road (link) having the highest shape correlation. ), A map matching process of matching the current position output from the current position calculation unit 46 is performed. Since the current position information obtained by the current position calculation unit 46 includes a sensor error, a map matching process is performed for the purpose of further improving the position accuracy. As a result, the current position often coincides with the traveling road.
[0032]
The trajectory storage unit 49 stores the information on the current location on which the map matching process has been performed by the map matching processing unit 47 as the trajectory data each time the vehicle travels a predetermined distance. The trajectory data is used to draw a trajectory mark on a road on a corresponding map for a road that has been traveled so far.
[0033]
The user operation analysis unit 41 receives a request from the user input to the input device 5, analyzes the contents of the request, and controls each unit of the arithmetic processing unit 1 so that a process corresponding to the request is executed. I do. For example, when the user requests a search for a recommended route, the user requests the map display unit 45 to display a map on the display 2 in order to set a departure place and a destination. It requests the route searching unit 42 to calculate the route.
[0034]
The route search unit 42 uses the Dijkstra method or the like to select a route that can reach the destination at a desired cost (travel time) among routes connecting the designated two points (departure place and destination), using map data. , And the obtained route is stored in the route storage unit 43 as a recommended route. In the present embodiment, the statistical traffic data stored in the map / statistical traffic data storage device 3, that is, the link of each link classified according to the type of day, for calculating the cost of the route connecting the two points. The traffic information statistical value for each time zone is used (see FIG. 3).
[0035]
The route guidance unit 44 compares the information on the recommended route stored in the route storage unit 43 with the information on the current location output from the map matching processing unit 47, and determines whether to proceed straight before passing through an intersection or the like, The user is notified by voice using the voice input / output device 4 using the voice input / output device 4, or the direction to be traveled is displayed on the map displayed on the display 2 to notify the user of the recommended route.
[0036]
Further, the actual travel time required from the departure point of the recommended route to the current position output from the map match processing unit 47 is measured. 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 to search for the recommended route, and according to the comparison result, To determine the necessity of re-searching the recommended route. When it is determined that there is a need for a re-search, the current position output from the map match processing unit 47 is set as a departure point, and the current time is set as a departure time, and a request for a re-search for a recommended route is made to the route search unit 42.
[0037]
The data reading unit 48 converts map data and statistical traffic data in an area required to be displayed on the display 2 or an area required for route search (an area including a starting point and a destination) into map / statistical data. It operates to prepare for reading from the traffic data storage device 3.
[0038]
The map display processing unit 45 receives the map data in the area required to be displayed on the display 2 from the data reading unit 48, and the graphic processing unit 51 uses the designated scale and drawing method to set roads and other map configurations. A map drawing command is generated so as to draw a mark such as an object, a current position, a destination, and an arrow for a guidance route. In addition, in response to the command output from the user operation analysis unit 41, the statistical traffic data required to be displayed on the display 2 is received from the data reading unit 48, and the traffic of each road is displayed on the map being displayed on the display 2. A map drawing command is generated so that the information statistic is superimposed and displayed.
[0039]
The menu display processing unit 50 receives a command output from the user operation analysis unit 41, and generates a menu drawing command so that the graphic processing unit 51 draws various types of menus and graphs.
[0040]
The graphics processing unit 51 receives the 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 into the VRAM 26.
[0041]
Next, the operation of the in-vehicle navigation device having the above configuration will be described.
[0042]
First, the recommended route search operation will be described.
[0043]
FIG. 7 is a flowchart for explaining a recommended route search operation of the vehicle-mounted navigation device to which the present embodiment is applied. This flow is started 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.
[0044]
First, the user operation analysis unit 41 sets the departure place, the destination, the departure date and time, and the presence / absence of expressway (road) priority in the route search unit 43 (S1001).
[0045]
Here, the departure place and the destination are determined by the user operation analysis unit 41 on the display 2 via the menu display processing unit 50 and the graphics processing unit 51, and on the map / statistical traffic data storage device 3 via the data reading unit 48. The information of the map components registered in the map data read from is displayed, and the user can select from the information of the displayed map components via the voice input / output device 4 or the input device 5. You may. Alternatively, the user can display information of a point (registered place) registered in a storage device such as the RAM 22 in advance, and the user can input the information of the displayed registered place through the voice input / output device 4 or the input device 5. You may make it select from inside. Further, the user operation analysis unit 41 specifies the map data 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 displayed map may be displayed, and the user may select a point by accepting designation of a point on the map via the voice input / output device 4 or the input device 5.
[0046]
When the current location is set as the departure place, the designation of the departure place by the user may be omitted. Also, when the current date and time are set as the departure date and time, the designation of the departure date and time by the user may be omitted. Further, when the designation of the presence / absence of high-speed priority is omitted from the user, a default condition (for example, no high-speed priority) may be set.
[0047]
When the departure place, the destination, the departure date and time, and the presence / absence of high-speed priority are set as described above, the user operation analysis unit 41 outputs a route search instruction to the route search unit 42. In response to this, the route search unit 42 reads out the above-described first conversion table from the map / statistical traffic data storage device 3 via the data reading unit 48. Then, using the first conversion table, the mesh ID of each mesh area included in the area including the departure place and the destination set in S1001 is specified. Then, the link data 312 registered in each of the map data 31 having the specified mesh ID is obtained from the map / statistical traffic data storage device 3 via the data reading unit 48 (S1002).
[0048]
Next, the route search unit 42 calculates a reference distance from the departure point set in S1001 to each mesh area having the mesh ID specified in S1002 (S1003). For example, the representative coordinates (for example, the coordinates of the center point) of the mesh area are registered together with the mesh ID in the first conversion table. Using the first conversion table, the route search unit 42 calculates the straight-line distance from the departure point set in S1001 to the representative coordinates of each mesh area having the mesh ID specified in S1002. Distance.
[0049]
Next, the route search unit 42 calculates a reference arrival time for each of the mesh areas having the mesh ID specified in S1002 (S1004). Specifically, the distance from the departure point to the mesh area calculated in S1003 is divided by the moving speed determined according to the presence or absence of the high-speed priority set in S1001, thereby calculating the reference moving time to this mesh area. I do. Then, the reference arrival time to the mesh area is calculated by adding the reference movement time to the departure time set in S1001. This processing is performed for each mesh area having the mesh ID specified in S1002.
[0050]
Here, the moving speed for obtaining the reference moving time is registered in the route search unit 42 in advance for each of the high speed priority and the non-high speed priority. The moving speed for obtaining the reference moving time may be registered in advance in consideration of not only the presence / absence of high-speed priority but also the distance from the departure place to the mesh area. FIG. 8 shows an example of a moving speed determination table preset in the route search unit 42. In this example, for each distance 351 from the departure place to the mesh area, the moving speed is set for each of the case 352 with high-speed priority and the case 353 without high-speed priority.
[0051]
Next, the route search unit 42 reads the above-described second conversion table from the map / statistical traffic data storage device 3 via the data reading unit 48, and uses the second conversion table to set the departure set in S1001. The type of day is specified (S1005).
[0052]
Next, the route search unit 43 specifies the statistical traffic data 32 having the mesh ID specified in S1002. Then, from the specified statistical traffic data 32 stored in the map / statistical traffic data storage device 3 via the data reading unit 48, the traffic information of each link associated with the type of the day specified in S1005. The traffic information statistical value of each link in the time zone including the reference arrival time to the mesh area having the mesh ID calculated in S1004 is obtained. This processing is performed for each of the mesh IDs specified in S1002 (S1006).
[0053]
The route search unit 43 connects the starting point and the destination by the Dijkstra method or the like using the link data and the traffic information statistical value of each link read from the map / statistical traffic data storage device 3 in S1002 and S1006. A recommended route is searched (S1007). At this time, if the traffic information statistical value of the candidate link is obtained in S1006, the travel time included in the traffic information statistical value is used as the cost of each candidate link of each link constituting the recommended route. . Here, when the traffic information statistical value includes the travel speed 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 of the candidate link. This is the cost. On the other hand, if the traffic information statistical value of the candidate link has not been obtained in S1006, the travel time included in the link data of the candidate link is used. Here, when the link data includes a travel speed instead of the travel time, the travel time of the link is calculated using the travel speed and the link length, and this is set as the cost. Then, for example, a route that minimizes the total cost of each link constituting the route connecting the departure place and the destination is searched.
[0054]
Next, the route search unit 43 determines the departure place, destination, departure date and time, whether or not there is high-speed priority set in S1001, and the link data obtained in S1002 and S1006 of each link constituting the recommended route searched in S1007. The traffic information statistical value is stored in the route storage unit 44 as recommended route information. Further, it instructs the map display processing unit 45 to display a recommended route. In response to this, the map display processing unit 45 controls the graphics processing unit 51 to display the recommended route together with the map on the display 2 according to the recommended route information stored in the route storage unit 44 (S1008). ).
[0055]
By the above processing, the travel time of each of the constituent links constituting the recommended route is determined by the departure time and the distance (reference distance) from the departure place to the mesh area where the constituent link is located. It will be obtained from statistical values.
[0056]
Next, the route guidance operation will be described.
[0057]
FIG. 9 is a flowchart for explaining a recommended route guidance operation of the vehicle-mounted navigation device to which the present embodiment is applied. In this flow, the user operation analysis unit 41 uses the voice input / output device 4 or the input device 5 to display the current location and the same date and time as the departure location and the departure date and time, for example, on the display 2. The recommended route is started by receiving a route guidance request.
[0058]
First, the user operation analysis unit 41 notifies the route guidance unit 44 of the route guidance request received from the user. In response, the route guidance unit 44 starts measuring the travel time using a built-in timer (not shown) or the like (S2001). In addition, information on the current location stored in the route storage unit 43, a point substantially the same as the current date and time, a departure place and a recommended date and time as a departure date and time, and map data stored in the map / statistical traffic data storage device 3 , The route guidance is started using a general (existing) route guidance technique (S2002).
[0059]
By the way, when the current position is newly output from the map match processing unit 47 during the processing of the route guidance (S2003), the route guidance unit 44 configures a certain link (the immediately preceding link) in which the current location constitutes the recommended route for the route guidance. ) Is moved to the next link (S2004). If it has not moved (No in S2004), the process returns to S2003, and waits for the map match processing unit 47 to output a new current location.
[0060]
On the other hand, if the user has moved (Yes in S2004), the route guidance unit 44 detects the travel time at that time, and uses this as the actual measurement value of the travel time up to the immediately preceding link (S2005). In addition, based on the information (traffic information statistics) of the recommended route to be route-guided, which is stored in the route storage unit 43, the links from the first link among the links constituting the recommended route to be route-guided The total travel time of each link up to the immediately preceding link is obtained, and this is set as the estimated travel time (S2006).
[0061]
Then, the route guidance unit 44 calculates the actual travel time value up to the immediately preceding link detected in S2005 and the estimated travel time up to the immediately preceding link obtained from the recommended route information stored in the route storage unit 43 in S2006. The difference is obtained, and the difference is compared with a predetermined value (S2007). Here, the predetermined value is a value for determining the necessity of re-searching the recommended route to the destination. For example, the estimated travel time to the immediately preceding link is A, the expected travel time to the destination is B, If the estimated error of the estimated travel time to the destination is C, it is set to (A / B) × C.
[0062]
As described above, in the present embodiment, the traffic information statistical value of the time zone including the estimated arrival time to the mesh area including the link is used as the traffic information statistical value used to determine the link configuring the recommended route. (See S1006 in FIG. 7). Therefore, if the difference between the actual travel time value up to the immediately preceding link and the expected travel time up to the immediately preceding link becomes large, the traffic information statistics used to determine each link following the immediately preceding link that constitutes the recommended route will be described. The value needs to be reviewed. Therefore, in the present embodiment, in S2007, the difference is compared with the predetermined value.
[0063]
If the difference is smaller than the predetermined value (No in S2007), the route guidance unit 44 returns to S2003 and waits for the map match processing unit 47 to output a new current location. On the other hand, if the difference is equal to or greater than the predetermined value (Yes in S2007), the route guidance unit 44 sets the current location, the current date and time as the departure point and the departure date and time, and determines whether the departure point, the destination, the departure date and time and the high-speed priority are set. Is set in the route search unit 42. Then, the route search unit 42 is caused to perform the above-described recommended route search processing (S1002 and subsequent steps in FIG. 7) (S2008). Then, when the new recommended route is stored in the route storage unit 43, the process returns to S2001. This flow ends when the current location reaches the destination.
[0064]
Hereinabove, one embodiment of the present invention has been described.
[0065]
In the present embodiment, the map / statistical traffic data storage device 3 stores the map data including the link data of each link constituting the road on the map and the link information of each link determined from the statistical value of the traffic information collected in the past. Statistical data including travel time or travel speed for each time zone is stored. Then, the on-vehicle navigation device uses the map data stored in the map / statistical traffic data storage device 3 and, for each mesh region, the reference of the mesh region determined according to the departure date and time and the distance from the departure place to the mesh region. A recommended route between the departure point and the destination is searched for using the traffic information statistical value of each link in the mesh area corresponding to the time zone including the arrival time.
[0066]
In this way, by changing the time zone of the traffic information statistical value used to determine each link constituting the recommended route according to the reference travel time from the departure place to the mesh area where each link exists, for example, It is possible to more accurately search for a recommended route with the minimum cost (travel time).
[0067]
In addition, the in-vehicle navigation device performs, in the route guidance processing, the actual travel time required from the departure point of the recommended route to the current position and the link of each link constituting the section from the departure point of the recommended route to the current position. A comparison is made with the travel time of the section obtained from the traffic information statistical value used for the determination, and the necessity of re-searching the recommended route is determined according to the comparison result. Then, when it is determined that there is a need to re-search for a recommended route, a recommended route to the destination is searched again using the current location as the departure point and the current time as the departure time. In this way, during route guidance, even if the vehicle is traveling on the current recommended route, it is possible to re-search for the recommended route so as to travel on the route with the minimum cost (travel time), for example. it can.
[0068]
Note that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist.
[0069]
For example, in the above-described embodiment, as the traffic information statistical value used for determining the link constituting the recommended route, the reference arrival time of the mesh area determined according to the departure date and time and the distance from the departure place to the mesh area including the link. The traffic information statistic corresponding to the time zone including is used.
[0070]
However, the present invention is not limited to this. For example, a traffic information statistic corresponding to a time zone including a reference arrival time of the mesh area determined according to the departure date and time and the distance from the departure place to the link may be used. In this case, the flow of FIG. 7 may be modified as follows. That is, in S1003, for each link included in each target mesh area, the distance from the departure place to the link (for example, the linear distance from the departure place to the start node of the link) is calculated. Next, in S1004, for each link included in each target mesh area, the reference travel time to the link is calculated by dividing the distance from the departure point to the link by the travel speed determined according to the presence or absence of high-speed priority. . Then, in S1006, for each link included in each target mesh area, the traffic information statistical value of the link associated with the type of the departure date, and the time zone including the reference arrival time to this link Get link traffic statistics. By doing so, the time zone of the traffic information statistic used to determine each link constituting the recommended route can be changed for each link. It is possible to search for a recommended route with higher accuracy.
[0071]
Further, in the above embodiment, the moving speed for obtaining the reference moving time is determined according to a combination of the presence or absence of high-speed priority and the distance from the departure place to the mesh area (see FIG. 8). .
[0072]
However, the present invention is not limited to this. The moving speed for obtaining the reference moving time may be determined in consideration of other search conditions in addition to these conditions or instead of these conditions. For example, when the weather is fine, the moving speed may be faster than when the weather is rainy.
[0073]
Further, in the above-described embodiment, an example in which the present invention is applied to a vehicle-mounted navigation device has been described. However, the present invention can be applied to a navigation device other than a vehicle-mounted navigation device.
[0074]
【The invention's effect】
As described above, according to the present invention, it is possible to accurately search for a recommended route using traffic information collected in the past.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vehicle-mounted navigation device to which an embodiment of the present invention is applied.
FIG. 2 is a diagram showing a configuration example of map data stored in a map / statistical traffic data storage device 3;
FIG. 3 is a diagram illustrating a configuration example of statistical traffic data stored in a map / statistical traffic data storage device 3;
FIG. 4 is a diagram illustrating a configuration example of a second conversion table for specifying a day type from a date;
FIG. 5 is a diagram illustrating a hardware configuration of an arithmetic processing unit 1;
FIG. 6 is a diagram illustrating a functional configuration of an arithmetic processing unit 1;
FIG. 7 is a flowchart for explaining a recommended route search operation of the vehicle-mounted navigation device to which the embodiment is applied;
FIG. 8 is a diagram illustrating an example of a moving speed determination table preset in a route search unit;
FIG. 9 is a flowchart for explaining a recommended route guidance operation of the vehicle-mounted navigation device to which the embodiment is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Operation 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, 11 ... In-vehicle LAN 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, 43 ... route storage unit, 44 ... route guidance unit, 45 ... map display processing unit, 46 ... current position calculation unit, 47: Map match processing unit, 48: Data reading unit, 49: Gauge Storage unit, 50 ... menu display processing unit, 51 ... graphics processing unit

Claims (4)

A route search method for a navigation device,
The navigation device includes map data including link data of each link constituting a road on the map, and travel time or moving speed for each time zone of each link determined from statistics of traffic information collected in the past. A storage device for storing the statistical data and
Setting steps for setting the departure time, departure place and destination of the route to be searched;
Using a map data and statistical data stored in the storage device, a route search step of searching for a recommended route between the departure point and the destination,
The route searching step uses, for each of the candidate links of the links constituting the recommended route, statistical data of a time zone determined according to the departure time and the distance from the departure place to the candidate link, to determine the candidate link. Determining a cost (moving time) for a route search of a navigation device. The route search method for a navigation device according to claim 1, wherein
In the map data, link data of a link existing in the mesh area is associated with each of a plurality of mesh areas obtained by dividing the map into a plurality of pieces,
The route searching step uses, for each of the candidate links of the links constituting the recommended route, statistical data of a time zone determined according to the departure time and the distance from the departure place to the mesh area where the candidate link exists. And determining the cost of the candidate link. The route search method for a navigation device according to claim 1 or 2,
The setting step also sets a search condition of a route to be searched,
The route searching step uses statistical data of a time zone including a time obtained by adding a moving speed determined by the search condition and a moving time determined from the distance to the departure time. Route search method. Stores map data including link data of each link constituting a road on the map, and statistical data including a travel time or a moving speed for each time zone of each link determined from a statistical value of traffic information collected in the past. Storage device,
Setting means for setting the departure time, departure place and destination of the route to be searched;
Route search means for searching for a recommended route between the departure place and the destination using map data and statistical data stored in the storage device,
The route search means uses, for each of the candidate links of the links constituting the recommended route, statistical data of a time zone determined in accordance with the departure time and the distance from the departure place to the candidate link, to determine the candidate link. A navigation device for determining a cost (moving time) for a route search of a vehicle.

Images