JP4100971B2 - Map data acquisition method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method in which an in-vehicle terminal equipped with a cache acquires map data from a center via a network. The present invention also relates to a method for acquiring and storing map data by an in-vehicle terminal equipped with a cache.
[0002]
[Prior art]
A network type navigation system has been developed that transmits map data and a route to a destination from a center having a map database to a vehicle-mounted terminal via a network.
[0003]
Japanese Laid-Open Patent Publication No. 2000-251196 discloses that route information and route additional information are separately transmitted from the center to the in-vehicle terminal and displayed in an overlapping manner on the in-vehicle terminal device side.
[0004]
[Problems to be solved by the invention]
In a system that uses a map etc. distributed from the network on a terminal device, if the same map etc. once acquired by the terminal device is obtained again, or if a map with a large file size is obtained, unnecessary communication charges and time will be spent. I need it. Further, it is desirable that the capacity of the storage device of the terminal device is small. Accordingly, an object of the present invention is to efficiently use a storage device of a terminal device and reduce reception capacity and reception time when acquiring map information and route guidance information from a network.
[0005]
[Means for Solving the Problems]
According to the method of the present invention, when a map data acquisition operation is started, a list of map data stored in the storage means is transmitted to the center device in advance, and an acquisition request for map data based on the current position is sent to the request. Correspondingly performed for the center apparatus for searching a map data among the map data requested is acquired from the center apparatus for map data that does not exist in the list.
[0006]
For the map data existing in the list, if the map data of the center is newer than the terminal device, the map data is acquired from the center .
[0007]
In addition, the map data acquired from the center is overwritten in the storage means .
[0008]
Further, map data and route guidance information are acquired from the center, and a map including the guidance route is created on the map data acquired based on the latitude and longitude information included in the route guidance information .
[0009]
Further, at least a part of the URL character string is used as a file name for storing the acquired map data in the storage means .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing an outline of the configuration of the system of the present invention. As shown in FIG. 1, this system has an in-vehicle terminal device 1 (hereinafter referred to as “terminal”) and a center device 2 (hereinafter referred to as “center”), and transmits and receives information to and from each other via a network 3 such as the Internet. It can be done.
[0014]
The terminal 1 includes a communication unit 11 that transmits / receives information to / from the center 2 via a network 3 such as the Internet, a control unit 12, a data storage unit 13, a vehicle position detection unit 14 such as a GPS receiver that detects the vehicle position, An input device 15 for inputting a departure place and a destination, a display device 16 for displaying a guidance route and a map, and a speaker 17 for voice guidance are provided. A mobile phone 111 can be used as the communication unit 11. The terminal control unit 12 includes a map acquisition setting unit 121, a map cache list generation unit 122, a map image composition unit 123, a data acquisition processing unit 124, a map drawing unit 125, and a locus drawing unit 126. The data storage unit includes a map image storage unit 131, a trajectory data storage unit 132, and a route-attached map image storage unit 133.
[0015]
The center 1 includes a communication unit 21, a control unit 22, a map search unit 23, a map database 24, a map deletion list generation unit 25, a map use frequency list 26 for each terminal, and a route search unit 27.
Example 1
In the first embodiment, the terminal 1 acquires map information from the center 2 by the acquisition method selected and set.
[0016]
FIG. 2 is a flowchart showing a procedure according to the first embodiment using the system of FIG. The control in each step is performed by the control unit 12 of the terminal and the control unit 22 of the center. The same applies to other flowcharts.
[0017]
First, when the terminal 1 is operated to perform the map acquisition setting, the “map file acquisition setting screen” of the display device 16 is displayed.
(1) Obtain from the network (In this case, the map file is obtained only from the network and cannot be obtained from the cache)
(2) Cache priority (If there is a desired map file in the cache, the cache map file is used preferentially)
(3) Used only from the cache (In this case, only the map file of the cache is used and cannot be obtained from the network)
The following three options are displayed. Here, “cache” means the storage device of the terminal as described above. The user selects one of the map information acquisition and setting methods (S1). Next, the user inputs information indicating that the current position is to be transmitted to the input device 15 of the terminal 1 (S2). Since the current position of the terminal is detected by the own vehicle position detection unit 14, this is transmitted to the center. When it is input that the current position is to be transmitted, a map acquisition request is generated (S3). When this request is generated, it is determined whether or not a map acquisition method is selected (S4). If not selected (No), the process returns to S1 and a map acquisition method is selected on the setting screen. If the map acquisition method is selected (Yes), it is determined whether “acquire from network” is selected (S5). If Yes, the map is acquired from the network (S6), and the map is displayed on the display device 16 (S11).
[0018]
On the other hand, if “acquire from network” is not selected in S5 (No), it is determined whether or not “cache priority” is set (S7). If Yes, it is determined whether the desired map is in the cache (S8). If not (No), the map is acquired from the network and displayed on the display device 16 of the terminal (S11). In the case of S8 (Yes), the map is acquired from the cache (S10) and displayed on the display device 16 of the terminal (S11). When it is not “cache priority” in S7 (No), only the cache is used (S9), so a map is acquired from the cache (S10) and displayed on the display device 16 (S11). The map acquisition setting is performed by the map acquisition setting unit 121 of FIG.
(Example 2)
In Example 2, when a terminal acquires map information, a map file list (hereinafter referred to as “map cache list”) stored in the terminal is transmitted to the center, and the map information is requested from the terminal. At this time, it is determined whether to use the map stored in the terminal or to transmit the map from the center and to provide the map.
[0019]
FIG. 3 is a flowchart illustrating a procedure according to the second embodiment. In FIG. 3, when the operation is started, a “map cache list” is transmitted from the terminal to the center ((1)). The “map cache list” includes a symbol for identifying a map in which area and the date and time when the map is acquired by the terminal. Next, the user inputs to the input device 15 that the current position of the terminal 1 is to be transmitted (S1). Since the current position of the terminal is detected by the own vehicle position detection unit, this is transmitted to the center. When an instruction to transmit the current position is input, a map acquisition request is generated (S2). Based on the map acquisition request, a map acquisition request is transmitted from the terminal to the center together with the current position ((2)). The center receives this and searches for a necessary map based on the current position of the in-vehicle terminal (S3). Next, based on the “map cache list” transmitted from the terminal, it is determined whether or not the searched map exists in the list (S4). If it exists (Yes), the acquisition date and time of the cache list map is the center. If it is not older than the acquisition date of the map (S5), if not older (Yes), the terminal is notified to use the cache map ((3)). However, when it is old (No), it is instructed to transmit a map from the center, and the map is transmitted from the center to the terminal ((4)). In S4, if it does not exist in the cache list (No), the map is transmitted from the center to the terminal ((4)). In response to this, the terminal displays the map stored in the cache or the map transmitted from the center on the display device 16 (S6). In addition, when a new map with the acquisition date and time is acquired from the cache with a map in the same area, the map acquired from the center is overwritten on the map in the same area held in the map image storage unit 131 of the terminal.
(Example 3)
In the third embodiment, the terminal transmits a map cache list to the center, selects a map with low use frequency at the center, transmits a list of maps to be deleted to the terminal, and the terminal transmits the list to the terminal based on the received deletion list. The map that is retained is deleted.
[0020]
FIG. 4 is a flowchart illustrating a procedure according to the third embodiment. In FIG. 4, when the operation is started, the user inputs an instruction to select deletion of the map file at the terminal (S1). When deletion of the map file is selected, the terminal generates a “map cache list” from the saved map file in the map cache list generation unit 122 and transmits it to the center ((1)). The “map cache list” includes a symbol for identifying a map in which area and the date and time when the map is acquired by the terminal. The center receives this, selects a map that is not frequently used from the transmitted maps in the “map cache list”, generates a map deletion list (S3), and transmits it to the terminal ((2)). Even if the map is not transmitted to the terminal at the center, the map used by the terminal is searched, so it is known which area the map is used by the terminal, and therefore the frequency of use is known. Based on the received map deletion list, the terminal deletes the map stored in the map image storage unit of the terminal (S4). Thus, by deleting a map that is not frequently used, the capacity of the storage unit of the terminal can be used effectively.
Example 4
In the fourth embodiment, the monochrome map received from the center is stored as a color image in the terminal.
[0021]
FIG. 5 is a diagram for explaining the fourth embodiment. FIG. 5 is a map transmitted from the center, and the terminal receives this map, recognizes marks such as a temple / shrine mark (卍), a post office mark (〒), etc., and stores them with colors. In addition, the color is changed according to the width of the road. The facility name and background are colored and stored. Thus, the visibility of the map can be improved without increasing the communication capacity by coloring the map on the terminal side. This operation is performed by the map image composition unit 123. Thus, since the map to be transmitted is monochrome, the transmission capacity can be reduced.
(Example 5)
In the fifth embodiment, when a plurality of maps transmitted from the center and stored in the terminal partly overlap, the overlapping part is deleted and a new map is synthesized and stored. .
[0022]
FIG. 6 is a diagram for explaining the fifth embodiment. As shown in FIG. 6A, when the map X and the map Y overlap each other at the portion Z, they are synthesized at the terminal, and a new map is generated and saved as shown in FIG. 6B. In the above example, two maps are combined, but overlapping portions can be deleted from three or more maps and newly combined.
(Example 6)
In the sixth embodiment, a map in which vehicle trajectory data is written on the displayed map is saved.
[0023]
FIG. 7 is a flowchart illustrating a procedure according to the sixth embodiment. In FIG. 7, the acquired map is first displayed (S1), and then the latitude and longitude of the vehicle are acquired from the vehicle position detection device 14 using GPS or the like at a predetermined time interval, for example, every second (S2). ). The acquired latitude and longitude are sequentially stored in the trajectory data storage unit 132 (S3). Next, it is determined whether or not the map display is finished (S4). For example, the map display ends when the route guidance ends and arrives at the destination. If the map display is not completed (No), the process returns to S2 and the acquisition of latitude and longitude is continued. If the map display is completed (Yes), the latitude and longitude of the route taken by the vehicle stored in the trajectory data storage unit 132 are extracted and written on the map (S5). Since the map also includes latitude and longitude data, the latitude and longitude of the route taken by the vehicle is written on the map based on the latitude and longitude data included in the map. Since the assembly of the latitude and longitude of the route through which the vehicle has passed is a travel locus of the vehicle, a map in which the route as the locus is written is generated, and is stored in the route-attached map image storage unit 133 ( S6). In S7, the acquired map is displayed, and the same operation is repeated. In this way, by writing the vehicle trajectory on the map and storing it, it is possible to recognize routes that are frequently used.
[0024]
In the above description, the trajectory is written in the map image. However, the trajectory can be generated as a transparent image, stored as a file different from the map image, and displayed on the map image when displayed. By not writing the trajectory on the map in this way, the map can be used for other purposes.
(Example 7)
In the seventh embodiment, route guidance information is written in the acquired map information and stored in the terminal.
[0025]
FIG. 8 is a flowchart showing a procedure according to the seventh embodiment. First, the user inputs the current position and destination of the vehicle to the input device 15 of the terminal 1 (S1), and requests the center to acquire a map and a guide route (S2). This request is transmitted from the control unit 12 via the communication unit 11 to the center 2 via the network together with the current position of the vehicle and the latitude and longitude of the destination ((1)). At the center, this is received by the communication unit 21 and sent to the map search unit 23 and the route search unit 27. The map search unit 23 searches for a map in a range including the current position and the destination, and the route search unit 27 searches for a guide route based on the current position and the latitude and longitude of the destination, and includes guidance information including route guidance information. An information file is generated (S3). The route guidance information included in this file is the latitude and longitude of the route, the latitude and longitude of the point to be a point, the guidance information of the intersection, and the like. The retrieved map and guidance information file are sent separately to the terminal ((2)).
[0026]
The terminal receives these files and first displays a map on the display device 16 (S4). Next, the latitude and longitude of the route included in the guidance information file are extracted (S5), and the guidance route is drawn on the map (S6). Then, the map including the guidance route is stored in the data storage unit of the terminal (S7). By storing the map including the guide route in the terminal in this way, it can be used when following the same route, so that it is not necessary to transmit from the center, and the transmission capacity can be reduced.
[0027]
Instead of drawing the guide route on the map based on the latitude and route of the route included in the guide information file on the terminal, the guide route can be drawn as a transparent image and saved as a separate file from the map image. it can.
(Example 8)
In the eighth embodiment, a URL character string is used as a file name when a map is stored in a cache.
[0028]
FIG. 9 is a diagram for explaining the eighth embodiment. FIG. 9 shows the form of a map stored in the terminal. The map is divided into predetermined areas. For example, “11, 12, 13, -----” for each divided map. "Is attached to the identification symbol. According to the present embodiment, when a map is stored in a cache, a URL character string is used as the file name of each divided map. For example, a file name “http://www.11.jp.ne.” Is assigned to the section 11 in FIG. By assigning the file name in this way, it is not necessary to create a new file name when saving the map. In addition, when checking whether a map to be used is in the cache, it is possible to search by URL. Therefore, there is no need to search from the cache list file, so no special function is required.
[0029]
【The invention's effect】
According to the present invention, it is possible to reduce the transmission capacity and time from the center by preferentially using the map stored in the cache. In addition, since a map that is not used frequently or a portion that overlaps a plurality of maps is deleted from the cache, the capacity of the cache can be reduced. In addition, the route used by the user can be recognized by generating the route locus on the terminal side.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a system configuration used in a method of the present invention.
FIG. 2 is a diagram illustrating a procedure according to the first embodiment.
FIG. 3 is a diagram showing a procedure of Example 2.
4 is a diagram showing a procedure of Example 3. FIG.
FIG. 5 is a diagram for explaining Example 4;
6 is a diagram for explaining a fifth embodiment; FIG.
7 is a diagram showing a procedure of Example 6. FIG.
8 is a diagram showing the procedure of Example 7. FIG.
FIG. 9 is a diagram for explaining an eighth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... In-vehicle terminal device 11 ... Communication part 111 ... Mobile phone 12 ... Control part 121 ... Map acquisition setting part 122 ... Map cache list generation part 123 ... Map image composition part 124 ... Data acquisition processing part 125 ... Map drawing part 126 ... Trajectory Drawing unit 13 ... data storage unit 131 ... map image storage unit 132 ... locus data storage unit 133 ... map image storage unit 14 with route ... own vehicle position detection unit 15 ... input device 16 ... display device 17 ... speaker 2 ... center device 21 ... Communication unit 22 ... Control unit 23 ... Map search unit 24 ... Map database 25 ... Map deletion list generation unit 26 ... Map usage frequency list 27 for each terminal ... Route search unit 3 ... Network

Claims (4)

A terminal device comprising a storage means obtains map data via a network,
At the start of the map data acquisition operation, a list of map data stored in the storage means is transmitted to the center device in advance , and a map data acquisition request based on the current position is searched for map data in response to the request done for the center device that,
Among the requested map data, map data that does not exist in the list is acquired from the center device ,
Regarding the map data existing in the list, when the map data of the center device is newer than the terminal device, the map data is acquired from the center device . The map data acquisition method according to claim 1, wherein map data acquired from the center device is overwritten in the storage unit. Map data and route guidance information are acquired from the center device, and a map including a guidance route is created on the acquired map data based on latitude and longitude information included in the route guidance information. The map data acquisition method according to claim 1 or 2.   4. The map data acquisition method according to claim 1, wherein at least a part of a character string of a URL is used as a file name for storing the acquired map data in the storage unit. 5.

Images