JP5345801B2 - Navigation device and guidance method thereof - Google Patents

Description

  The present invention relates to a navigation device mounted on a vehicle or the like.

  Conventionally, in a navigation device that searches and guides a route from a current location to a destination, a technique for obtaining an ellipse that focuses on the current location and the destination and obtaining traffic information from an information center or the like for a range included in the obtained ellipse There is. This is described in Patent Document 1, for example.

JP 2004-125504 A

  In the navigation device as described above, the traffic information acquisition range is focused on the current location and the destination, and the sum of the distance from the focus increases the distance of the straight line connecting the current location and the destination by a predetermined ratio. It is limited to the range of the ellipse that is the locus of the point that has the same value.

  Therefore, if the guide route from the current location to the destination is significantly longer than the straight distance from the current location to the destination, such as detouring the bay, the route deviates from the range of the ellipse. For this reason, effective traffic information in the vicinity of the guidance route may not be acquired.

  An object of the present invention is to provide a technique for acquiring traffic information in the vicinity of a guide route without omission within a necessary range.

In order to solve the above problems, the navigation device of the present invention is based on route search means for searching for a route from the current position of the vehicle to the destination, and the route length of the route searched by the route search means. comprising a region selection means for selecting an area for acquiring traffic information, and information acquisition means for acquiring the communication traffic information about the city selected by the area selecting unit from the outside, the region selection unit, on a predetermined map A mesh based on an area constituted by a set of points is selected as an area for acquiring the traffic information, and a time required to reach the mesh that is the selected area is set for each mesh. The mesh that is obtained using the required time is excluded from the selected area if the required time is longer than the predetermined time, and the point on the predetermined map And the linear distance from the current position to a point on the predetermined map, the distance obtained by adding the linear distance from the destination to a point on the predetermined map, the path length of the route searched by said route searching means It is a point which becomes below the predetermined distance exceeding.

Also, for example, a navigation device guidance method, wherein the navigation device searches for a route from the current position of the host vehicle to a destination and the route length of the route searched in the route search step. There are a region selection step of selecting an area for acquiring traffic information, running, and information acquisition step of acquiring the communication traffic information for the selected area from the outside in the region selection step, in the region selecting step, A mesh based on a region constituted by a set of points on a predetermined map is selected as a region for acquiring the traffic information, and a time required to reach the mesh that is the selected region is determined for each mesh. Select a mesh that is obtained using a predetermined required time, and that the required time is longer than the predetermined time. The points on the predetermined map are the linear distance from the current position of the vehicle to the point on the predetermined map, and the linear distance from the destination to the point on the predetermined map. Is a point that is equal to or less than a predetermined distance exceeding the route length of the route searched by the route search means .

  A navigation device to which an embodiment of the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an in-vehicle navigation device 100 to which the present invention is applied. As shown in the figure, the in-vehicle navigation device 100 includes an arithmetic processing unit 1, a display 2, a storage device 3, a voice input / output device 4 (a microphone 41 as a voice input device, and a speaker 42 as a voice output device), an input A device 5, a ROM device 6, a vehicle speed sensor 7, a gyro sensor 8, a GPS (Global Positioning System) receiver 9, an FM multiplex broadcast receiver 10, and a beacon receiver 11 are provided.

  The arithmetic processing unit 1 is a central unit that performs various processes. For example, the current location is detected based on information output from the various sensors 7 and 8, the GPS receiver 9, the FM multiplex broadcast receiver 10, or the beacon receiver 11. Further, map data necessary for display is read from the storage device 3 or the ROM device 6 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 or the like stored in the storage device 3 or the ROM device 6, an optimum route (recommended route) connecting the starting point (current location) and the destination instructed by the user is searched. Further, the user is guided using the speaker 42 and the display 2.

  The arithmetic device 1 has a configuration in which devices are connected by a bus 25. The arithmetic processing unit 1 includes a CPU (Central Processing Unit) 21 that executes various processes such as numerical calculation and control of each device, and a RAM (Random Access Memory) that stores map data, arithmetic data, and the like read from the storage device 3. ) 22, a ROM (Read Only Memory) 23 for storing programs and data, and an I / F 24 which is an interface for connecting various hardware to the arithmetic unit 1.

  The display 2 is a unit that displays graphics information generated by the arithmetic processing unit 1. The display 2 is configured by a liquid crystal display, an organic EL display, or the like.

  The storage device 3 is composed of at least a readable / writable storage medium such as an HDD (Hard Disk Drive) or a nonvolatile memory card.

  The storage medium includes a link table 200, which is map data (including link data of links constituting roads on a map) necessary for a normal route search device, a mesh table 300, and a candidate mesh table 400. It is remembered.

  FIG. 2 is a diagram showing the configuration of the link table 200. The link table 200 includes, for each mesh identification code (mesh ID) 201, which is a partitioned area on the map, link data 202 of each link constituting a road included in the mesh area.

  For each link ID 211 that is a link identifier, the link data 202 includes coordinate information 222 of two nodes (start node and end node) constituting the link, a road type 223 indicating the type of road including the link, and a link length. Link length 224 indicating link travel time 225, link ID (connection link ID) of a link connected to each of the two nodes constituting the link, start connection link, end connection link 226, common name of road including the link (for example, , “Ring Hachi street” etc.).

  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 225 may be a link travel time associated with each condition such as date / time and weather.

FIG. 3 is a diagram showing the configuration of the mesh table 300. The mesh table 300 is
It is a table for storing information for specifying and managing meshes, and is stored in advance in a storage device.

  The mesh table 300 includes mesh data 302 that is information on the mesh area for each mesh identification code (mesh ID) 301 that is a partitioned area on the map.

  The mesh data 302 includes representative point coordinates 321 that are representative points representing the mesh (usually the intersection of the diagonal lines of the mesh), mesh range specifying information 322 that specifies the position and range of the mesh (the northwest corner coordinates 323 of the mesh, mesh North-south length 324 indicating the north-south length, east-west length 325 indicating the east-west length of the mesh, etc., mesh travel time 326 indicating the time required to pass through the mesh, and finally traffic information from the external information center The last download time 329 indicating the time at which the data is acquired is included.

  Note that the mesh travel time 326 indicating the time required to pass through the mesh is “general” 327, which is the time required to travel on a general road, and a toll road such as an expressway. It is subdivided into “paid” 328 which is the time required to pass.

  The last download time 329 indicates the time when the download is completed when traffic information related to links belonging to the mesh is downloaded in units of meshes.

  FIG. 4 is a diagram showing the configuration of the candidate mesh table 400. As shown in FIG.

  The candidate mesh table 400 is a table that stores information about meshes that are candidates for downloading traffic information and the like, and is created and discarded by a maximum range selection process, a mesh arrival time calculation process, and the like, which will be described later.

  The candidate mesh table 400 includes a mesh ID 401, a scheduled arrival time 402 that is a scheduled time to reach the mesh, and a download target flag 403 that indicates whether or not the traffic information is to be downloaded.

  A mesh ID 401 is a mesh ID of a mesh to be downloaded such as traffic information.

  The estimated arrival time 402 is an estimated arrival time calculated according to statistical information or the like when reaching the mesh in units of meshes, not in units of links.

  The download target flag 403 indicates a result of determining whether or not to actually download a mesh that is a candidate for downloading traffic information and the like.

  In actual downloading, if the latest traffic information can be acquired only once at the time of use, it is efficient in terms of download amount, freshness of traffic information, and the like.

  Therefore, a determination result as to whether or not to actually download among the download candidate meshes is stored as the download target flag 403.

  Returning to FIG. The voice input / output device 4 includes a microphone 41 as a voice input device and a speaker 42 as a voice output device. The microphone 41 acquires sound outside the in-vehicle navigation device 100 such as a voice uttered by a user or another passenger.

  The speaker 42 outputs a message to the user generated by the arithmetic processing unit 1 as an audio signal. The microphone 41 and the speaker 42 are separately arranged at a predetermined part of the vehicle. However, it may be housed in an integral housing. The vehicle-mounted navigation device 100 can include a plurality of microphones 41 and speakers 42.

  The input device 5 is a device that receives an instruction from the user through an operation by the user. The input device 5 includes a touch panel 51, a dial switch 52, and other hardware switches (not shown) such as scroll keys and scale change keys.

  The touch panel 51 is mounted on the display surface side of the display 2 and can see through the display screen. The touch panel 51 specifies a touch position corresponding to the XY coordinates of the image displayed on the display 2, converts the touch position into coordinates, and outputs the coordinate. The touch panel 51 includes a pressure-sensitive or electrostatic input detection element.

  The dial switch 52 is configured to be rotatable clockwise and counterclockwise, generates a pulse signal for every rotation of a predetermined angle, and outputs the pulse signal to the arithmetic processing unit 1. The arithmetic processing unit 1 obtains the rotation angle from the number of pulse signals.

  The ROM device 6 is composed of at least a readable storage medium such as a ROM (Read Only Memory) such as a CD-ROM or a DVD or an IC (Integrated Circuit) card. In this storage medium, for example, moving image data, audio data, and the like are stored.

  The vehicle speed sensor 7, the gyro sensor 8, and the GPS receiver 9 are used in the in-vehicle navigation device 100 to detect the current location (own vehicle position).

  The vehicle speed sensor 7 is a sensor that outputs a value used to calculate the vehicle speed. The gyro sensor 8 is composed of an optical fiber gyro, a vibration gyro, or the like, and detects an angular velocity due to the rotation of the moving body. 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. The direction is measured and transmitted to the arithmetic processing unit 1.

  The FM multiplex broadcast receiver 10 receives an FM multiplex broadcast signal transmitted from an FM multiplex broadcast station. FM multiplex broadcasting includes VICS (Vehicle Information Communication System: Registered Trademark) information, current traffic information, regulatory information, SA / PA (service area / parking area) information, parking information, weather information, and FM multiplex general information. As text information provided by radio stations.

  The beacon receiving device 11 includes VICS (Registered Trademark, Vehicle Information and Communication System) information and the like, current traffic information, regulation information, SA / PA (service area / parking area) information, parking information, weather information, emergency alerts, and the like. Receive. For example, it is a receiving device such as an optical beacon that communicates by light and a radio beacon that communicates by radio waves.

  FIG. 5 is a functional block diagram of the arithmetic processing unit 1.

  As illustrated, the arithmetic processing unit 1 includes a main control unit 101, a maximum range selection unit 102, an arrival time calculation unit 103, an update unit 104, an input reception unit 105, and an output processing unit 106. .

  The main control unit 101 is a central functional unit that performs various processes, and controls other processing units according to the processing content. The main control unit 101 also performs navigation processing (for example, display of traffic information, display of current position, route search, route guidance, etc.), which is the original basic operation of the in-vehicle navigation device 100. Further, the current time is output in response to a request from each processing unit.

  The maximum range selection unit 102 selects the maximum range that needs to receive road traffic information.

  Specifically, first, the maximum range selection unit 102 calculates the route length of the route calculated from the current position of the host vehicle and the destination.

  Then, the maximum range selection unit 102 includes a range on the map that includes a point that is less than or equal to the path length when the distance from the current position and the distance from the destination are added (this point is an elliptical point) Is calculated).

  Then, a mesh whose mesh representative point is included in the calculated range on the map is extracted and stored in the candidate mesh 400.

  The arrival time calculation unit 103 calculates, for each mesh stored in the candidate mesh 400, a time when it will reach the mesh when traveling starts from the current position, and stores it in the candidate mesh 400. Furthermore, the arrival time calculation unit 103 stores a mesh whose arrival time is within a predetermined time from the current time as a mesh to be downloaded.

  Specifically, the arrival time calculation unit 103 specifies, for each of the meshes stored in the candidate mesh 400, the mesh that takes the shortest time to reach the mesh from the current position using the Dijkstra method or the like. To do.

  Here, the Dijkstra method is calculated from the cost (for example, an average speed based on statistical information) of a route (link separated by a node) connecting two designated points (current position, destination or stopover point). A method of searching for a route that minimizes (travel time).

  However, in the example of the present embodiment, calculation similar to the Dijkstra method is performed by substituting the representative point of the mesh for the node and substituting the virtual line connecting the representative point of the mesh adjacent to the upper, lower, left, and right sides of the mesh for the link. Apply the law. In such a case, when calculating the cost, the travel time set for the mesh to which the representative point on the side that is the end point of the virtual line connecting the representative points of the mesh belongs is used as the cost of the virtual line connecting the representative points of the mesh. To do.

  Alternatively, when calculating the cost, the travel time may be determined based on the travel time of the two meshes. Specifically, the travel time set for the mesh to which the representative point on the side serving as the starting point of the virtual line connecting the representative points of the mesh belongs, and the travel time set for the mesh to which the representative point on the side serving as the end point belongs, It is good also as using the average value of.

  That is, a path in which a plurality of meshes that are adjacent to each other in a lattice shape are sequentially connected is specified as a path. In addition, a route cost is obtained by accumulating costs previously given to the mesh included in the route in the order of the route, and a route that minimizes the cost is specified as the shortest route.

  Then, the arrival time calculation unit 103 calculates the arrival time that is the shortest for each of the meshes stored in the candidate mesh 400 and adds the current arrival time to the arrival time.

  In addition, the arrival time calculation unit 103 stores the calculated arrival time in the candidate mesh 400, and a mesh scheduled to arrive after a time obtained by adding a predetermined time (for example, 60 minutes) to the current time is not a download target. Determine and store in candidate mesh table 400.

  The update unit 104 downloads traffic information about the mesh to be downloaded among the meshes stored in the candidate mesh table 400.

  Specifically, the update unit 104 extracts a mesh to be downloaded from the meshes stored in the candidate mesh table 400, and transmits a request to an external information center or the like to transmit traffic information regarding the extracted mesh. .

  Then, the update unit 104 receives traffic information transmitted from an external information center or the like, and updates the traffic information in the storage device 3.

  The input receiving unit 105 is a processing unit that receives an instruction input from the user via the microphone 41, the touch panel 51, and the dial switch 52, and transfers this to each processing unit.

  The output processing unit 106 is a functional unit that displays screen output on the display 2. Receives screen data and display candidates in the area that is required to be displayed on the display 2, and uses the specified drawing method to create a dialog for roads, other map components, current location, destination, recommended route, and message information A screen drawing command is generated so as to draw. Then, the generated command is transmitted to the display 2.

  The main control unit 101, maximum range selection unit 102, arrival time calculation unit 103, update unit 104, input reception unit 105, and output processing unit 106 are realized by the CPU 21 executing a program loaded into the RAM 22 or ROM 23. The

  Next, the operation of the in-vehicle navigation device 100 configured as described above will be described.

  FIG. 6 is a flowchart showing the entire flow of the maximum range selection process.

  When the main control unit 101 receives a processing request after the vehicle navigation device 100 is powered on, the main control unit 101 executes this flow.

  The main control unit 101 calculates the current position of the vehicle (step S001).

  Specifically, the main control unit 101 uses the GPS receiver 9 to measure the current position of the vehicle.

  At the same time, the main control unit 101 acquires the traveling state of the vehicle by the gyro sensor 8, corrects the current position obtained by the GPS receiver 9, and performs map matching to estimate the current position of the vehicle.

  The main control unit 101 receives a destination input from the user via the input receiving unit 105 (step S002).

  Next, the main control unit 101 performs a route search by specifying a route from the current position to the destination by the Dijkstra method or the like (step S003).

  Then, the maximum range selection unit 102 calculates the path length (hereinafter referred to as “d”) of the path specified in step S003 (step S004).

  The route length d is the predicted travel distance when traveling on the route from the current position calculated in step S001 to the destination received in step S002.

  Next, the maximum range selection unit 102 selects the mesh ID 301 of the first record in the mesh table 300 (step S005).

  Specifically, the maximum range selection unit 102 acquires the mesh ID 301 by specifying the first record sorted in ascending order using the mesh ID 301 as a key, for example, among the records in the mesh table 300.

Next, the maximum range selection unit 102 acquires the representative point coordinates 321 of the mesh ID selected in step S005 from the mesh table 300 (step S006).
Next, the maximum range selection unit 102 acquires a linear distance (hereinafter referred to as a) between the representative point coordinates 321 acquired in step S006 and the current position calculated in step S001 (step S007).

  Next, the maximum range selection unit 102 acquires a linear distance (hereinafter referred to as b) between the representative point coordinates 321 acquired in step S006 and the destination received in step S002 (step S008).

  Next, the maximum range selection unit 102 adds the value obtained by adding a calculated in step S007 and b calculated in step S008 to the path length d calculated in step S004 according to the value of d. It is determined whether or not it is equal to or less than a value obtained by adding a predetermined value α that changes (for example, α is a value that is 0.3 times the path length d) (step S009).

  That is, the maximum range selection unit 102 determines whether or not the following expression (1) is established.

a + b = <d + α (1)
The points satisfying Equation (1) are limited to an elliptical region including all of the route calculated in Step S003, the current position, and the destination.

  When the value of a + b is not less than or equal to the value of d + α (“No” in step S009), the maximum range selection unit 102 performs a process of step S012 described later.

  When the value of a + b is equal to or smaller than the value of d + α (“Yes” in step S009), the maximum range selection unit 102 acquires the mesh ID 301 of the record selected in step S005 and stores it in the candidate mesh table 400. It adds (step S010).

  Specifically, the maximum range selection unit 102 acquires the mesh ID 301 of the record selected in step S005 and stores it as the mesh ID 401 of the candidate mesh table 400.

  Next, the maximum range selection unit 102 determines whether or not the determination in step S009 has been made for all the records in the mesh table 300 (step S011).

  When the determination in step S009 is made for all the records in the mesh table 300 (“Yes” in step S011), the maximum range selection unit 102 ends the maximum range selection process.

When the determination in step S009 has not been performed for all records in the mesh table 300 (“No” in step S011), the maximum range selection unit 102 selects the mesh of the next record that has not been selected in the mesh table 300. ID 301 is selected and the process is performed from step S006 (step S012).
The above is the flow of the maximum range selection process.

  By the maximum range selection processing described above, only meshes that are within the range of the predetermined elliptical area (representing the expression (1)) among all the meshes stored in the navigation device 100 are extracted, and candidates are extracted. It can be stored in the mesh table 400.

  Next, mesh arrival time calculation processing for calculating the arrival time for each mesh stored in the candidate mesh table 400 will be described with reference to FIG.

  FIG. 7 is a diagram illustrating a processing flow of mesh arrival time calculation processing.

  The mesh arrival time calculation process is started when the main control unit 101 detects the end of the maximum range selection process shown in FIG.

  The main control unit 101 acquires the mesh ID of the mesh to which the current position belongs (step S101).

  Specifically, the main control unit 101 measures the current position of the vehicle using the GPS receiver 9.

  In addition, the traveling state of the vehicle is acquired by the gyro sensor 8, the current position obtained by the GPS receiver 9 is corrected, and map matching is performed to estimate the current position of the vehicle.

  Then, the main control unit 101 specifies a mesh to which the current position belongs and acquires a mesh ID.

  Next, the arrival time calculation unit 103 selects the mesh ID 401 of the first record in the candidate mesh table 400 (step S102).

  Specifically, the arrival time calculation unit 102 specifies the first record sorted in ascending order using the mesh ID 401 as a key, for example, among the records of the candidate mesh table 400, and acquires the mesh ID 401.

  Next, the arrival time calculation unit 103 calculates and stores the time to reach the mesh identified by the mesh ID acquired in step S102 (step S103).

  Specifically, the arrival time calculation unit 103 takes the shortest time to reach the mesh identified by the mesh ID selected in step S102 from the mesh ID to which the current position belongs acquired in step S101. Is identified.

  In order to specify this mesh, as described above, a calculation method similar to the Dijkstra method is used to calculate the total cost of a path constituted by a plurality of meshes adjacent to each other using the cost for each mesh. .

  In calculating the cost, the arrival time calculation unit 103 uses the general 327 when the route is searched with priority on general roads, and uses the pay 328 when priority is given to toll roads such as expressways. calculate.

  The arrival time calculation unit 103 calculates the arrival time that is the shortest calculated, adds it to the current time, calculates the arrival time, and stores it as the expected arrival time 402 of the candidate mesh table 400.

  Next, the arrival time calculation unit 103 determines whether or not the arrival time calculated in step S103 is included within a predetermined time (for example, within 60 minutes) from the current time (step S104).

  If it is not included within the predetermined time (“No” in step S104), the arrival time calculation unit 103 performs step S107 described later.

  If it is included within the predetermined time (“Yes” in step S104), the arrival time calculation unit 103 stores the mesh identified by the mesh ID selected in step S102 as a download target (step S105).

  Specifically, the arrival time calculation unit 103 searches the candidate mesh table 400 based on the mesh ID selected in step S102, and sets “Yes” in the download target flag 403 of the corresponding record.

  Next, the arrival time calculation unit 103 determines whether or not the determination in step S104 has been made for all records in the candidate mesh table 400 (step S106).

  When the determination in step S104 is made for all records in candidate mesh table 400 (“Yes” in step S106), arrival time calculation unit 103 ends the mesh arrival time calculation process.

  When the determination in step S104 is not performed for all records in candidate mesh table 400 (“No” in step S106), arrival time calculation unit 103 selects the next unselected record in candidate mesh table 400. The mesh ID 401 is selected, and the processing is performed from step S103 (step S107).

  The above is the flow of the mesh arrival time calculation process.

  Through the mesh arrival time calculation process, a mesh that can reach within a certain time (for example, 60 minutes) is extracted from the candidate meshes, and traffic information and the like can be stored in the candidate mesh table 400 as a mesh to be downloaded.

  Next, download processing for downloading traffic information for a mesh to be downloaded among meshes stored in the candidate mesh table 400 will be described with reference to FIG.

  FIG. 8 is a diagram showing a processing flow of download processing.

  The download process is started when the main control unit 101 detects the end of the mesh arrival time calculation process shown in FIG.

  Alternatively, the download process may be started by the main control unit 101 at a predetermined cycle (for example, every 30 minutes), or when the vehicle travels a predetermined distance (for example, 15 km). Also good.

  The update unit 104 acquires all the mesh IDs 401 of records whose download target flag 403 is set to Yes from the candidate mesh table 400 (step S201).

  For example, in the example of FIG. 4, the mesh ID 401 of the record whose mesh ID 401 is “96443682” and the record whose record is “823364580” is acquired.

  Next, the update unit 104 requests an information center (not shown) to transmit traffic information for the mesh ID acquired in step S201 via a wireless communication network such as a mobile phone network, and the transmitted traffic information. Is stored in a storage area of predetermined traffic information (not shown) of the storage device 3 (step S202).

  The above is the flow of the download process.

  Through the download process, traffic information about the candidate mesh that is the download target can be acquired.

  FIG. 9 is a diagram schematically showing the traffic information acquisition range in this embodiment.

  As shown in FIG. 9, since the route 1002 connecting the current position 1000 of the own vehicle and the destination 1001 sandwiches the bay 1008, the current position 1000 of the own vehicle and the destination are required to move through the land 1009. When a large detour is made with respect to a straight line connecting the ground 1001, traffic information around the detour route 1002 needs to be acquired.

  Therefore, according to the present invention, assuming that the point 1003 is a point such that a + b = d + α, the traffic information is obtained by narrowing down to a mesh in which the representative point 1007 is included in the range of the ellipse 1006 formed by the locus drawn by the point 1003. .

  Here, the value of d + α is always equal to or greater than d if the value of α is zero or a positive real number. Therefore, the value of a + b does not become smaller than the value of d, which is the path length. That is, the point on the path 1002 is always included in the ellipse 106. Therefore, traffic information around the route 1002 can always be acquired.

  Furthermore, traffic information is not acquired for meshes whose predicted time to arrive is slow (it takes a predetermined time or more to reach), so that traffic information can be acquired only for meshes around the current position 1000 of the vehicle. As a result, traffic information can be acquired with the minimum necessary traffic.

  FIG. 10 shows a conventional technique in which the current position 1100 and the destination 1101 are focused by the conventional technique, and the mesh to be downloaded is determined by an ellipse 1110 set according to the focal distance (regardless of the path length). It is a schematic diagram when used.

  As described above, in the conventional technique shown in the schematic diagram of FIG. 10, when the route is forced to travel on the land 1109 while largely bypassing the bay 1108, the mesh around the route 1102 around the route 1102 is downloaded. The mesh may not be included.

  By using the navigation device 100 to which the present embodiment is applied, an effect of avoiding the situation in which traffic information around the route 1102 cannot be acquired can be obtained.

  The embodiment of the present invention has been described above.

  The present invention is not limited to the above embodiment. The above embodiment can be variously modified within the scope of the technical idea of the present invention.

  For example, in the above-described embodiment, when the download process shown in FIG. 8 is performed again according to a predetermined cycle, duplicate information is displayed when the download interval is shorter than the update interval of information provided by the information center. There is a possibility of getting. This may be avoided.

  That is, the download process shown in FIG. 11 may be performed.

  FIG. 11 is a diagram showing a processing flow of download processing modified from the first embodiment.

  The update unit 104 selects a mesh ID 401 for the first record from among the records for which the download target flag 403 is set to Yes from the candidate mesh table 400 (step S211).

  For example, in the example of FIG. 4, the mesh ID 401 of the record whose mesh ID 401 is “96443382” is selected.

  Next, the update unit 104 reads the mesh table 300 and acquires the last download time 329 of the record corresponding to the mesh ID selected in step S211.

  Then, the current time is determined whether or not a predetermined time (for example, 60 minutes) has elapsed since the last download time (step S212).

  If the predetermined time has not elapsed (“No” in step S212), the updating unit 104 starts the process of step S215 without processing steps S213 and S214 described later.

If the predetermined time has elapsed (“Yes” in step S212), the update unit 104
A storage device that requests transmission of traffic information targeted for the mesh ID selected in step S211 via a wireless communication network such as a mobile phone network to an information center (not shown) and receives the transmitted traffic information. 3 is stored in an area for storing predetermined traffic information (not shown) (step S213).

  Next, the updating unit 104 searches the mesh table 300 for the corresponding mesh ID record, and stores the time when step S213 was performed as the last download time 329 (step S214).

  Next, the update unit 104 determines whether or not the determination in step S212 has been made for each of the records for which the download target flag 403 of the update mesh table 400 is set to Yes (step S215).

  When the determination in step S212 is made for each of the records for which the download target flag 403 is set to Yes (“Yes” in step S215), the update unit 104 ends the download process.

  If the determination in step S212 has not been made for all of the records for which the download target flag 403 is set to Yes (“No” in step S215), the update unit 104 sets the download target flag 403 to Yes. The mesh ID 401 of the next unselected record among the records that have been selected is selected, and the process is performed from step S212 (step S216).

  The above is the modified flow of download processing.

  By deforming in this way, it is possible to reduce the possibility of re-downloading traffic information that has not been updated since the previous download.

  That is, it is possible to reduce unnecessary communication by not downloading duplicate information.

  Further, for example, in the above embodiment, the arrival time for each mesh is calculated by the Dijkstra method in the mesh arrival time calculation process, but the present invention is not limited to this.

  That is, a route search to a representative point of the mesh is performed, and the arrival time when traveling on the searched route may be the mesh arrival time.

  By doing in this way, it becomes possible to specify the range which acquires traffic information based on more exact arrival time.

  Further, for example, information to be downloaded in the download process is not limited to traffic information, but may be map information difference update information, weather information, or the like.

  For example, in the case of weather information, it is possible to appropriately acquire arrival information such as a typhoon whose situation changes according to the time based on the predicted time to reach each mesh.

  In the first embodiment, the mesh travel time 326 of the mesh table 300 is not limited to the time required to pass.

  For example, it is good also as a mesh travel speed which is the information regarding the speed for calculating the time required to drive | work the mesh. Specifically, it is assumed that the mesh travel speed is a value determined in advance using an average value of travel speed and the like.

  In that case, when calculating the cost in the process of step S103 of the mesh arrival time calculation process, the arrival time calculation unit 103 uses the mesh travel speed of the general 327 when the route is searched with the general road priority. If a search is made with priority on toll roads, it is calculated using the mesh travel speed of toll 328.

  Specifically, when a route is searched with priority given to general roads, the arrival time calculation unit 103 sets the east-west length 325 to a general 327 mesh to obtain the mesh travel time if the route passes the mesh east-west. Find mesh travel time by dividing by travel speed.

  By doing in this way, it becomes possible to calculate the arrival time using the average travel speed for each mesh instead of the travel time information for each mesh.

  In the first embodiment, the traffic information downloaded in step S202 of the download process requests information by specifying a time zone, and acquires traffic information according to the specified time zone. May be.

  Specifically, in step S202, the update unit 104 acquires the estimated arrival time 402 of the candidate mesh table 400 for the mesh ID acquired in step S201. Then, the update unit 104 requests an information center (not shown) to transmit traffic information including the acquired estimated arrival time and mesh ID via a wireless communication network such as a mobile phone network, and the arrival information transmitted from the information center. Traffic information in a time zone close to the scheduled time is received and stored in a storage area of predetermined traffic information (not shown) in the storage device 3.

  By doing in this way, it becomes possible to acquire the traffic information of the area | region shown with a mesh according to the time which is going to drive | work, Therefore The information to acquire can be narrowed down.

  Therefore, it becomes possible to suppress the traffic volume of the first embodiment equally while increasing the accuracy of the traffic information.

  In addition, by doing in this way, it is possible to acquire in advance information corresponding to the estimated arrival time for an area that is not along the recommended route.

  As yet another modification, in the first embodiment, it is assumed that the traffic information downloaded in step S202 of the download process is set for each time zone, and the update unit 104 is scheduled to reach the mesh. The traffic information acquired according to the above may be displayed on the display 2.

  Specifically, in step S202, the update unit 104 receives traffic information and stores it in a storage area of predetermined traffic information (not shown) in the storage device 3. Then, the update unit 104 specifies the estimated arrival time to the area indicated by the mesh by the estimated arrival time 402 of the candidate mesh table 400.

  Then, the update unit 104 instructs to select and output to the display 2 information on a time zone that includes the estimated arrival time in the area indicated by the mesh from the acquired traffic information.

  By doing in this way, since it becomes possible to display the traffic information of the area shown with a mesh according to the time which is going to run, it becomes possible to raise the certainty of the traffic information shown to a user. .

  The above is a modification.

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

FIG. 1 is a schematic configuration diagram of an in-vehicle navigation device to which an embodiment of the present invention is applied. FIG. 2 is a diagram illustrating a configuration example of a link table stored in the storage device. FIG. 3 is a diagram illustrating a configuration example of a mesh table stored in the storage device. FIG. 4 is a diagram illustrating a configuration example of the candidate mesh table stored in the storage device. FIG. 5 is a diagram illustrating a functional configuration of the arithmetic processing unit. FIG. 6 is a flowchart of the maximum range selection process. FIG. 7 is a flowchart of the mesh arrival time calculation process. FIG. 8 is a flowchart of the download process. FIG. 9 is a diagram schematically showing the traffic information acquisition range in one embodiment of the present invention. FIG. 10 is a diagram schematically illustrating a traffic information acquisition range according to the related art. FIG. 11 is a flowchart of a modification download process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Arithmetic processing part, 2 ... Display, 3 ... Memory | storage device, 4 ... Voice output device, 5 ... Input device, 6 ... ROM device, 7 ... Vehicle speed sensor 8 ... Gyro sensor, 9 ... GPS receiver, 10 ... FM multiplex broadcast receiver, 11 ... Beacon receiver, 21 ... CPU, 22 ... RAM, 23 ... ROM, 24 ... I / F, 25 ... Bus, 41 ... Microphone, 42 ... Speaker, 51 ... Touch panel, 52 ... Dial switch, 100 ... In-vehicle navigation device, DESCRIPTION OF SYMBOLS 101 ... Main control part, 102 ... Maximum range selection part, 103 ... Arrival time calculation part, 104 ... Update part, 105 ... Input reception part, 106 ... Output processing part

Claims (6)

A navigation device,
Route search means for searching for a route from the current position of the vehicle to the destination;
Based on the route length of the route searched by the route search means, an area selection means for selecting an area for acquiring traffic information;
Information acquisition means for acquiring traffic information about the area selected by the area selection means from outside by communication;
The area selecting means selects a mesh based on an area constituted by a set of points on a predetermined map as an area for acquiring the traffic information, and a time required to reach the mesh that is the selected area Is determined using a predetermined required time provided for each mesh, meshes that have a longer required time than a predetermined time are excluded from the selected region,
The point on the predetermined map is a distance obtained by adding a linear distance from the current position of the vehicle to the point on the predetermined map and a linear distance from the destination to the point on the predetermined map. Is a point that is equal to or less than a predetermined distance exceeding the route length of the route searched by the route search means .
A navigation device characterized by that. The navigation device according to claim 1,
In the process of selecting a region based on the region as a region for acquiring the information, the region selecting unit selects a predetermined mesh including a representative point in the region as a region for acquiring the information.
A navigation device characterized by that. The navigation device according to claim 1 or 2,
The information acquisition means does not acquire the information for a region where the information is acquired within a predetermined time.
A navigation device characterized by that. The navigation device according to any one of claims 1 to 3,
Further, the area selection means obtains a time required to reach the selected area,
The information acquisition means acquires information about the area selected by the area selection means based on the required time;
A navigation device characterized by that. The navigation device according to any one of claims 1 to 3,
The area selecting means obtains a time required to reach the selected area;
The information about the region selected by the region selecting means is information set in advance according to the time zone,
Furthermore, it comprises information presenting means for identifying and presenting information according to the time zone based on the required time.
A navigation device characterized by that. A navigation device guidance method comprising:
The navigation device
A route search step for searching for a route from the current position of the vehicle to the destination;
An area selection step for selecting an area for acquiring traffic information based on the route length of the route searched in the route search step;
An information acquisition step of acquiring the traffic information of the region selected in the region selection step from outside by communication; and
In the region selection step, a mesh based on a region constituted by a set of points on a predetermined map is selected as a region for acquiring the traffic information, and required for reaching the mesh that is the selected region The time is obtained using a predetermined required time provided for each mesh, and the mesh having the required time longer than the predetermined time is excluded from the selected region,
The point on the predetermined map is a distance obtained by adding a linear distance from the current position of the vehicle to the point on the predetermined map and a linear distance from the destination to the point on the predetermined map. Is a point that is equal to or less than a predetermined distance exceeding the route length of the route searched by the route search means .
A guidance method characterized by that.

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