JP2004077254A - Navigation system, map difference data distribution device, and on-vehicle navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower communication cost and shorten communication time and to allow an user to perform version upgrade of map data without complication. <P>SOLUTION: In a server of a navigation system, a first route searched based on current map data used on a terminal and a second route searched based on the latest map data on the server are compared (S21 to S25). When a different part is detected (S26), only the map data in block unit corresponding to the different part are extracted from the latest map data (S27), and the extracted map date is distributed to the terminal side as map difference data (S28). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a server that provides a service for distributing various types of information related to navigation and an in-vehicle terminal (navigation device) that has a function of searching for a route to a destination based on map data are communicably connected to each other. With regard to a navigation system, particularly when a navigation device having a rewritable storage medium storing map data downloads the latest map data from a server side and updates the map data, the communication efficiency is improved. Regarding useful techniques.
[0002]
[Prior art]
In a typical vehicle-mounted navigation device that is generally known, a CPU that controls all processes related to navigation, a storage device such as a CD-ROM or a DVD-ROM that stores map data, a display device, and a current device of the vehicle. A GPS (Global Positioning System) for detecting a position, a gyro and a vehicle speed sensor for detecting a traveling direction and a traveling speed of the own vehicle, and a VICS (Vehicle Information and Communication) for receiving traffic information. System) A receiver and the like are provided. The CPU reads out the map data including the current position of the vehicle from the storage device, draws a map image around the position of the vehicle on the display screen based on the map data, and indicates the current position of the vehicle. The vehicle position mark is superimposed and displayed on the display screen, the map image is scrolled according to the movement of the vehicle, or the vehicle position mark is moved while the map image is fixed on the screen. At a glance where they are currently driving.
[0003]
In addition, the in-vehicle navigation device is usually provided with a function (route guidance function) for guiding a user to easily travel on a road to a destination without making a mistake. According to the route guidance function, the CPU calculates the optimal route from the starting point (typically, the current position of the vehicle) to the destination using the map data by simulation such as a horizontal search method or a Dijkstra method. Is performed, and the searched route is stored as a guide route, and the guide route can be distinguished from other roads on the map image during traveling (for example, by changing the color or increasing the line width). Display), and when the vehicle approaches a point (intersection) where the course should be changed on the guidance route within a predetermined distance, an enlarged view of the intersection is displayed on a map image, The user can grasp the optimal route to the destination.
[0004]
As described above, the navigation mode using only the map data of the in-vehicle device (a storage device such as a CD-ROM) is referred to as a navigation mode in which the route search can be performed by the vehicle alone (that is, “on-board”). This is also referred to as "local navigation" and is the mainstream form of in-vehicle navigation devices in the current technology.
[0005]
On the other hand, there is a “communication navigator” as a type of navigation that has recently attracted attention, which provides route guidance and the like using route search results and map data acquired from outside the vehicle by communication. It is expected that car navigation systems will become the mainstream in the future. A typical communication navigator transmits, for example, position data relating to the current position and destination of the own vehicle via a mobile phone or the like to a server connected via the Internet or the like, based on the position data. The server searches for an optimal guidance route (recommended route) for the vehicle, downloads the search result by communication, and performs route guidance for the vehicle.
[0006]
In order to provide highly accurate information guidance on road information, POI information, and the like in a navigation device that performs route search and route guidance (route guidance) based on an in-vehicle map database, whether local navigation or communication navigation, It is desirable that the map data stored in the map database reflect the latest information as much as possible. For example, if the shape of the road is changed, new facilities (convenience stores, family restaurants, gas stations, banks, etc.) are created around the road, or if the location of the facilities is changed, the changed Since the latest information does not exist in the original database, it is necessary to update (upgrade) the map data to match the latest information.
[0007]
Conventionally, map data is upgraded by replacing a storage medium (a fixed medium such as a CD-ROM or a DVD-ROM, a rewritable medium such as an HDD) that stores the map data itself, or This has been implemented by a method of rewriting data via communication means.
[0008]
[Problems to be solved by the invention]
When updating (upgrading) the map data by replacing the storage medium, it is necessary to send the storage medium (possibly together with the navigation device body) to a maker to have all data rewritten, or to update the latest data. It is necessary to have the disk replaced with a new disk (storage medium) on which the data has been written.
[0009]
For this reason, it is very complicated and wasteful in terms of cost, and furthermore, it takes a considerable amount of time before the data-updated storage medium is returned to the user.
[0010]
On the other hand, when updating (upgrading) map data by rewriting data by communication, data is transferred to a server such as an information center by a communication means such as a mobile phone and the latest information is reflected in a map database. Can be done.
[0011]
However, in this method, since the map data is transferred by communication, the communication cost is high, and the amount of communication data is enormous compared to the case of the normal character information transfer, so the latest information is reflected. It takes a considerable amount of time to download the map data from the server side and complete the rewriting of the database, which is not practical.
[0012]
In addition, the terminal (navigation device) does not always need all information (the latest map data) downloaded from the server. For example, for users traveling mainly in the Kanto region and its surroundings, obtaining the latest road information in the Hokkaido region has no utility, so that the time and cost required to obtain the information are wasted. .
[0013]
In addition, in both the method of exchanging the storage medium and the method of rewriting the data by communication, there is such a trouble that the user has to be conscious of updating (upgrading) the map data.
[0014]
The present invention has been made in view of the above-described problems in the related art, and in obtaining the latest map data necessary for performing highly accurate information guidance by communication, the communication cost is reduced and the communication time is reduced. It is an object of the present invention to provide a navigation system that can shorten the time and update (upgrade) map data without complicating the user.
[0015]
It is another object of the present invention to provide a map difference data distribution device and a vehicle-mounted navigation device provided on the server side in the above navigation system.
[0016]
[Means for Solving the Problems]
According to the present invention, in order to solve the above-described problems of the related art, a server that has a map database that stores at least the latest map data and performs a distribution service of various types of information related to navigation, and is capable of communicating with the server. A vehicle-mounted terminal having a rewritable storage medium connected to and storing map data necessary for navigation, and having a function of performing a route search to a destination based on the map data. When a search command is issued, the position data of the current position and the destination of the vehicle and the user identification data for specifying the map data used by the user of the vehicle-mounted terminal are transmitted to the server. Searching for a first route to the destination based on the user identification data and the position data, A second route to the destination is searched based on the position data by referring to the latest map data stored in the first map data, and the searched first and second routes are compared. Detecting a difference between the latest map data, extracting only map data in block units corresponding to the difference portion from the latest map data, and transmitting the extracted map data to the on-board terminal as map difference data. A navigation system is provided.
[0017]
According to the navigation system of the present invention, when a route search command is issued on the terminal side, each position data of the current position and the destination of the vehicle and the map data used by the user (that is, stored in the storage medium) User identification data for specifying the destination map data) is transmitted to the server, and the server refers to the latest map data stored in the map database on the basis of the received data, and the server determines the destination. To the first route (based on the current map data used on the terminal side) and the second route (based on the latest map data on the server) to When a difference portion is detected by comparison, only the map data in block units of the corresponding portion is extracted from the latest map data and distributed to the terminal side as map difference data. It is.
[0018]
As described above, according to the present invention, the transfer data from the terminal to the server is only the position data and the user identification data. On the server side, the current map data used on the terminal side and the latest map data on the server are used. Compared with the data, when a difference is detected, only the corresponding part of the map data is downloaded, so the communication cost can be reduced, and the communication time can be shortened even in the narrow band. Can and is very efficient.
[0019]
Also, on the terminal side, only when necessary (when a route search command is issued), the map data is updated based on the map difference data distributed from the server in real time. Version upgrade of map data can be performed. This makes it possible to provide highly accurate information guidance regarding road information, POI information, and the like.
[0020]
According to another aspect of the present invention, there is provided a map difference data delivery device provided in a server which provides a delivery service of various types of information related to navigation, for communicating with a navigation device mounted on each vehicle. Communication means, a map database storing at least the latest map data, and control means for controlling input / output of the communication means and the map database, wherein the control means controls the navigation of each vehicle via the communication means When receiving from the device the current position and destination data of the vehicle and the user identification data specifying the map data in use by the user of the navigation device, based on the user identification data and each position data, A first route to the destination is searched, and the latest map data stored in the map database is searched. A second route to the destination based on the position data with reference to the data, and comparing the searched first and second routes to detect a difference between the two, Extracting only map data in block units corresponding to the difference portion from the latest map data, and distributing the extracted map data as map difference data via the communication means. A distribution device is provided.
[0021]
According to still another aspect of the present invention, there is provided an in-vehicle navigation device communicably connected to a server equipped with the above-described map difference data distribution device, the display device providing guidance information to a user. A rewritable storage medium storing map data necessary for navigation, a position detecting means for detecting a current position of the vehicle, an information inputting means for inputting information necessary for searching for a destination or a route, A display device, a storage medium, a control means for controlling the input and output of the position detecting means and the information input means, and the control means, when a route search command is issued through the information input means, the position of each of the positions. Transmitting the data and the user identification data to the server, and downloading the map difference data from the server, The map data is updated by overwriting the map data stored in the storage medium, and the second route is searched based on the updated map data, and the searched second route is displayed on the display device. There is provided an in-vehicle navigation device characterized by being displayed on a screen.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0023]
FIG. 1 schematically shows a configuration of a navigation system according to an embodiment of the present invention.
[0024]
The navigation system according to the present embodiment includes a server (information center) 10 that provides a distribution service of various types of navigation-related information (map data including road information and POI information, route guidance information, VICS information, and the like); And an in-vehicle terminal 30 (navigation device) communicably connected to the vehicle. The server 10 is equipped with a device 20 for delivering map difference data which characterizes the present invention. The map difference data delivery device 20 is provided with a communication device for communicating with each in-vehicle terminal 30 (navigation device). A map database 22 having a large capacity; and a control unit 23 for controlling input and output of the communication unit 21 and the map database 22.
[0025]
The map database 22 includes a database (version 1, version 2,..., The latest version) in which current map data used by the user of each in-vehicle terminal 30 (navigation device) is stored for each version. As will be described later, a user database (DB) that stores information on the download history of the map difference data for each user is provided.
[0026]
FIG. 2 schematically shows the configuration of the vehicle-mounted terminal 30 (navigation device) in the navigation system.
[0027]
In the in-vehicle terminal (navigation device) 30, reference numeral 31 denotes a hard disk drive (HDD), and a disk 31a driven by the HDD 31 has an appropriate size according to the scale level (1 / 12,500, 1/25000, 1/50000, etc.). It stores map data divided into longitude and latitude widths of various sizes. This map data includes road data for display, property data relating to the location of various facilities and properties (gas stations, convenience stores, family restaurants, etc.), road data for route search, and the like. , And a coordinate set of points (nodes) expressed in latitude and longitude. The map data stored in the disk 31a is rewritten (that is, updated) when the latest map data is downloaded from the server 10 under the control of the control unit 47 as described later. Has become.
[0028]
Reference numeral 32 denotes an operation unit for operating a navigation device main body 40 described later, and has, for example, a form of a remote control transmitter. Although not specifically shown, the remote control transmitter is appropriately provided with various operation buttons, a joystick, and the like for selecting various menus, various items, and the like on the display screen and executing the selected menu and the like. Reference numeral 33 denotes a communication device such as a mobile phone or an in-vehicle phone for communicating with the server 10 via the Internet, and 34 receives a GPS signal transmitted from a GPS satellite to determine the longitude and latitude of the current position of the vehicle. The GPS receiver to detect, 35 indicates a self-contained navigation sensor. The self-contained navigation sensor 35 includes an angle sensor 35a such as a gyro for detecting the traveling direction of the own vehicle, and a distance sensor 35b that generates a pulse for each fixed traveling distance. Used to detect
[0029]
Reference numeral 36 denotes a display device such as an LCD, and 37 denotes a speaker. The display device 36 basically provides navigation-related guidance information (a map around the current position of the vehicle, a guidance route from the departure point to the destination, The present position of the car (own vehicle position mark), other guidance information, etc. are provided to the user on the screen, and specifically, the acquisition of map difference data performed by the on-board terminal 30 and the The guidance information related to the route search / display based on is displayed on the screen. The speaker 37 provides the user with voice guidance information on the navigation and route guidance information based on the acquisition of the map difference data.
[0030]
In the navigation apparatus main body 40, reference numeral 41 denotes a map data read control unit for reading map data from the disk 31a via the HDD 31, and reference numeral 42 denotes a buffer memory for temporarily storing map data read by the map data read control unit 41. , 43, 44, 45, and 46 indicate interfaces (I / F) connected to the operation unit 32, the communication device 33, the GPS receiver 34, and the self-contained navigation sensor 35, respectively. Reference numeral 47 denotes a control unit constituted by a microcomputer or the like. The control unit 47 stores a navigation program (a program for performing a route search process and a display output control necessary for route guidance based on the route search process). In accordance with this program, the current position of the vehicle is detected based on a signal output from the GPS receiver 34, and the traveling speed (vehicle speed) of the vehicle is determined based on a signal output from the self-contained navigation sensor 35. ) Or by controlling the map data reading control unit 41 to read the map data to be displayed from the disk 31a to the buffer memory 42 via the HDD 31 or use the map data read into the buffer memory 42. Navigation, such as searching for a guidance route from the starting point (the current position of the vehicle) to the destination based on the search conditions set It executes various processes according. When executing various processes related to the navigation, the control unit 47 has a function of controlling acquisition of map difference data performed by the in-vehicle terminal 30 and route search / display processing based on the map difference data, as described later.
[0031]
Reference numeral 48 denotes a map drawing unit that performs a map image drawing process using the map data read into the buffer memory 42. Reference numeral 49 denotes various menu screens (operation screens), own vehicle position marks, cursors, and the like according to the operation status. Reference numeral 50 denotes an operation screen / mark generation unit for generating various marks, and a guidance route storage unit for storing data relating to the guidance route. The guidance route storage unit 50 stores data relating to all nodes (coordinates of points expressed in latitude and longitude) from the departure point to the destination of the guidance route searched by the control unit 47. Reference numeral 51 denotes a guidance route drawing unit which reads guidance route data (node sequence) from the guidance route storage unit 50 and displays the guidance route in a different display mode (color is changed, line width is different from other roads). , Etc.).
[0032]
Reference numeral 52 denotes an image synthesizing unit, based on the control of the control unit 47, the map image drawn by the map drawing unit 48, the guidance route drawn by the guidance route drawing unit 51, the operation screen / mark generation unit. It has a function of superimposing the operation screen, various marks, and the like generated in 49 on the screen of the display device 36. The image synthesizing unit 52 also has a function of displaying on the screen of the display device 36 guidance information relating to acquisition of map difference data performed by the on-board terminal 30 and route search / display based on the map difference data, as described later. Reference numeral 53 denotes an audio output unit that outputs an audio signal (guidance information related to navigation, route guidance information based on acquisition of map difference data, etc.) to the speaker 37 based on control from the control unit 47.
[0033]
Reference numeral 54 denotes a memory (user identification data storage) such as a RAM for storing user identification data for specifying a user of the vehicle-mounted terminal 30. The user identification data includes a control unit 23 on the server 10 side. Contains information necessary to identify the user.
[0034]
In the navigation system configured as described above (the map difference data distribution device 20 provided in the server 10 and the navigation device 30 as an in-vehicle terminal), the communication unit 21 is a “communication unit”, and the control unit 23 is “ The control unit ", the disk 31a is a" rewritable storage medium ", the operation unit 32 is an" information input unit ", the GPS receiver 34 is a" position detection unit ", the control unit 47 is a" control unit ", The user identification data storages 54 correspond to “memory means”.
[0035]
Hereinafter, regarding the processing performed in the navigation system according to the present embodiment, the processing flow illustrated in FIG. 3 (the acquisition of the map difference data performed by the terminal 30 and the route search / display processing based thereon) and the processing flow illustrated in FIG. This will be described with reference to FIGS. 5 to 7 for supplementary explanation of these processing flows together with the map difference data distribution processing.
[0036]
First, referring to FIG. 3, in a first step S11, the user operates the operation unit 32 (remote control transmitter) to set a destination. At this time, if necessary, a passing point on the way to the destination (such as which route to reach the destination) is set, and various conditions (whether to give priority to toll roads or priority to general roads). Whether to go, whether to give priority to shortening the traveling distance or shortening the traveling time, etc.) is also set. The data of the set destination and the like is input to the control unit 47 via the interface 43.
[0037]
In the next step S12, a guidance route for the own vehicle to travel is searched by the local navigation. Specifically, the control unit 47 performs map data reading control based on the input destination data and the departure point data set as the departure point based on the current position of the vehicle detected by the GPS receiver 34. By controlling the unit 41, the map data in the range from the departure point to the destination is read out from the disk 31a via the HDD 31 to the buffer memory 42, and further, by referring to the data stored in the guidance route storage unit 50, A guidance route (first route) connecting the departure place and the destination is searched by a horizontal search method or the like.
[0038]
In the next step S13, the searched guidance route is displayed on the screen of the display device 36 via the image combining unit 52 under the control of the control unit 47, and route guidance is started (local navigation).
[0039]
For example, as schematically shown in a screen display example of FIG. 5A, a guidance route GR1 (the first route) from the departure point A (the current position of the vehicle) to the destination B is displayed on the screen 60 of the display device. Route) on the map image. At this time, the guidance route GR1 is displayed in a display mode different from that of other roads (for example, displayed in a conspicuous color, or made thicker, etc.) so that the user can easily identify it. Thus, the user can grasp the guidance route GR1 (first route) through which the vehicle should be guided to the destination B through the screen 60 of the display device.
[0040]
In the next step S14, the position data indicating the current position and the destination of the vehicle and the user identification data are stored in the center (the server 10) through the communication device 33 (such as a mobile phone) under the control of the control unit 47. ). Thereafter, the server 10 performs processing related to distribution of map difference data, which will be described later.
[0041]
In the next step S15, in a state where the own vehicle is guided along the guidance route GR1 (first route) as described above, the control unit 47 transmits the map difference data from the server 10 via the communication device 33. It is determined whether it has been received (YES) or not (NO). If the result of the determination is YES, the process proceeds to step S16, and if the result of the determination is NO, the processing flow ends.
[0042]
In the next step S16, the map difference data received via the communication device 33 is overwritten on the map data currently stored in the disk 31a via the HDD 31 under the control of the control unit 47, and the map data is overwritten. Update (version of map data).
[0043]
In the next step S17, the control unit 47 reads map data based on the data of the destination and the data of the current position of the vehicle detected by the GPS receiver 34 in the same manner as the processing performed in step S12. The controller 41 is controlled to read out the map data (in this case, the updated and upgraded map data) in the range from the departure point to the destination from the disk 31a via the HDD 31 to the buffer memory 42 and further guide the data. With reference to the data stored in the route storage unit 50, a guidance route (second route) connecting the departure place and the destination is searched.
[0044]
In the last step S18, the route (second route) searched based on the upgraded map data is combined with the initially searched route (first route) together with the image combining unit 52 based on the control from the control unit 47. Is displayed on the screen of the display device 36 via a PC, and after a predetermined time has elapsed, the display of the first route is erased to display only the second route, and route guidance is performed. Then, this processing flow is “end”.
[0045]
At the time of displaying the first and second routes, for example, as schematically shown in a screen display example of FIG. 5B, the target is displayed on the screen 60 (one screen) of the display device from the current position A of the vehicle. The first and second routes GR1 and GR2 reaching the ground B are superimposed on the map image and displayed. At this time, the routes GR1 and GR2 are displayed in different display modes so that the user can easily identify them. In the example of FIG. 5B, the old route (the first route GR1) is displayed in a broken line mode so as to be relatively inconspicuous as compared with the new route (the second route GR2). Of course, the display mode of each route is not limited to this. For example, the new route GR2 may be displayed in a color more conspicuous than the old route GR1, or the old route GR1 may be displayed in a blinking manner.
[0046]
Alternatively, as schematically shown in the screen display example of FIG. 5C, the screen of the display device is divided into two, and the old route (first route GR1) is displayed on one screen (left screen L). Then, a new route (second route GR2) may be displayed on the other screen (right screen R).
[0047]
By simultaneously displaying the new route GR2 and the old route GR1 on the screen 60 (L, R) of the display device in this manner, the user can obtain the effect of downloading the map difference data from the server 10 (comparing to the old route). Display of the new route). In addition, since the display of the old route GR1 is turned off after a lapse of a predetermined time, the new route GR2 to which the vehicle should be guided to the destination B through the display screen can be grasped.
[0048]
Next, referring to FIG. 4, in the first step S21, in the control unit 23 of the distribution device 20 of the server 10, each position data (vehicle position, destination) and user identification data are transmitted from the terminal 30 via the communication unit 21. Is determined (YES) or not (NO). If the determination is YES, the process proceeds to step S22. If the determination is NO, the determination process is repeated until the data is received.
[0049]
In the next step S22, based on the received user identification data, in the control unit 23, information on the version of the map data (map data used by the user of the terminal 30) from the map database 22 and the map for the terminal 30 Search for information on the download history of the difference data.
[0050]
In the next step S23, the control unit 23 considers the version information of the searched map data and the download history information of the map difference data, and based on the received position data (vehicle position, destination), Search for a first route to.
[0051]
In the next step S24, the control unit 23 refers to the latest version of the map data stored in the map database 22 and reaches the destination based on the received position data (vehicle position, destination). Search for a second route.
[0052]
In the next step S25, the control unit 23 causes the first route searched in step S23 (that is, the route searched based on the current map data used by the terminal 30) and the second route searched in step S24. (That is, a route searched based on the latest map data on the server 10). In performing this comparison, the control unit 23 not only determines whether or not each route is mutually the same in terms of position and shape, but also determines the surrounding roads along each route and the surroundings along the route. It is also determined whether or not the locations (POIs), landmarks, and the like of various existing facilities and properties are the same as each other.
[0053]
For example, as schematically shown in the comparative example of FIG. 6A, it is determined whether the searched routes GR1 and GR2 are the same in position and shape (that is, whether different routes are searched). In comparison, if the positions and shapes are the same, as shown schematically in the comparative example of FIG. 6B, the surrounding roads PR1 and PR2 along the respective routes GR1 and GR2 are positioned and Whether or not the shapes are the same (that is, whether or not there is a new or closed road) is compared. Further, as shown schematically in the comparative examples of FIGS. Whether the positions (POIs) M1 to M3 of the objects and the like existing in the vicinity along the routes GR1 and GR2 and the positions and shapes of the landmarks LM1 and LM2 are the same (that is, whether the POIs / la Domaku to compare whether there is no).
[0054]
In the next step S26, the control unit 23 determines whether a difference between the two routes GR1 and GR2 has been detected (YES) or not (NO) based on the comparison process illustrated in FIG. If the result of the determination is YES, the process proceeds to step S27, and if the result of the determination is NO, the process ends.
[0055]
In the next step S27, the control unit 23 refers to the map database 22 and extracts only map data (map difference data) in block units corresponding to the difference portion from the latest version of map data.
[0056]
Here, the block unit map data corresponding to the difference portion is, for example, as schematically shown in FIG. 7, when the latest version of the map data is divided into a plurality of block units, the difference between the two routes GR1 and GR2. Block-based map data (portions indicated by BM1 to BM3 in the example of FIG. 7) including the portion where occurs.
[0057]
In the last step S28, the map data extracted by the control unit 23 is distributed as map difference data to the terminal 30 via the communication unit 21, and information on the map data version for the user in the map database 22 and map difference data Update the download history information for as needed. Then, this processing flow is “end”.
[0058]
As described above, according to the navigation system (the map difference data distribution device 20 provided in the server 10 and the navigation device 30 as the vehicle-mounted terminal) according to the present embodiment, the terminal 30 performs the route search. At this time, each position data of the current position and the destination of the vehicle and the user identification data are transmitted to the server 10, and the server 10 further stores the latest data stored in the map database 22 based on the received data. Referring to the version of the map data, the first route (based on the current map data used on the terminal 30) and the second route (the latest route on the server 10) to the destination are referred to. Search based on the map data), and when the two are compared and a difference is detected, the block And extract only the map data, so that delivery to the terminal 30 side as the map difference data.
[0059]
As described above, in the present system, the data transferred from the terminal 30 to the server 10 is only the position data and the user identification data. On the server 10 side, the current map data used by the terminal 10 and the current Compared to the latest map data, and when a difference is detected, only the corresponding part of the map data is downloaded, so that communication costs and communication time can be reduced. Can and is very efficient.
[0060]
In addition, since the map data is updated on the terminal 30 side based on the map difference data distributed in real time from the server 10 only when the route search is performed, the map data is upgraded without the user being aware of it. Can be performed. As a result, highly accurate information guidance on road information, POI information, and the like can be provided to the user.
[0061]
When the map data is upgraded on the terminal 30 side, the server 10 may be notified separately to change the version information of the map data for the user in the map database 22.
[0062]
【The invention's effect】
As described above, according to the navigation system (the map difference data distribution device and the in-vehicle navigation device) according to the present invention, the latest map data necessary for providing highly accurate information guidance is obtained by communication. In this case, the communication cost and the communication time can be reduced, and the map data can be updated (upgraded) without complicating the user.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a configuration of a navigation system according to an embodiment of the present invention.
FIG. 2 is a block diagram schematically showing a configuration of a vehicle-mounted terminal (navigation device) in the system of FIG.
FIG. 3 is a flowchart showing an example of map difference data acquisition and route search / display processing performed by the terminal side in the system of FIG. 1;
FIG. 4 is a flowchart showing an example of map difference data distribution processing performed by a server in the system of FIG. 1;
FIG. 5 is a diagram illustrating an example of a screen display related to route guidance.
FIG. 6 is a diagram for supplementarily explaining the processing flow of FIG. 4;
FIG. 7 is an explanatory diagram of map difference data.
[Explanation of symbols]
10. Server (information center)
20: map difference data distribution device
21 ... communication unit (communication means),
22 ... Map database,
23 ... control unit (control means),
30 ... on-board terminal (navigation device)
31a disk (rewritable storage medium),
32 ... operation unit (information input means),
33 ... communication equipment,
34 ... GPS receiver (position detecting means)
36 ... display device,
40 ... Navigation device body,
47 ... control unit (control means),
52 ... image synthesis unit
54 ... user identification data storage unit (memory means)
60 (L, R) ... display screen,
BM1 to BM3 ... map difference data in block units,
GR1: The searched guidance route (first route),
GR2: The searched guidance route (second route).

Claims (10)

A server that has a map database that stores at least the latest map data, and that performs a distribution service of various information related to navigation;
An on-board terminal communicably connected to the server, having a rewritable storage medium storing map data necessary for navigation, and having a function of searching for a route to a destination based on the map data; ,
When a route search command is issued in the in-vehicle terminal, each position data of the current position and the destination of the vehicle and user identification data for specifying map data used by the user of the in-vehicle terminal are transmitted to the server. And
The server searches for a first route to the destination based on the user identification data and the position data, and refers to the latest map data stored in the map database. Searching for a second route to the destination based on
When comparing the searched first and second routes and detecting a difference between the two, only map data in block units corresponding to the difference portion is extracted from the latest map data, and the extracted map data is extracted. A navigation system for transmitting the generated map data to the in-vehicle terminal as map difference data. The said in-vehicle terminal, when downloading the said map difference data from the said server, updates the said map data by overwriting the said map difference data with the map data stored in the said storage medium. 2. The navigation system according to 1. A map difference data distribution device provided in a server that performs a distribution service of various information related to navigation,
Communication means for communicating with a navigation device mounted on each vehicle;
A map database containing at least the latest map data,
Control means for controlling input and output of the communication means and the map database,
The control means transmits, from the navigation device of each vehicle via the communication means, each position data of a current position and a destination of the vehicle and user identification data for specifying map data used by a user of the navigation device. Upon receipt, a first route to the destination is searched for based on the user identification data and each position data, and each position is referred to by referring to the latest map data stored in the map database. Searching for a second route to the destination based on the data,
When comparing the searched first and second routes and detecting a difference between the two, only map data in block units corresponding to the difference portion is extracted from the latest map data, and the extracted map data is extracted. A map difference data distribution device, which distributes the obtained map data as map difference data via the communication means. The map database further stores map data for each version used by a user of each of the navigation devices and data relating to a download history of map difference data for each user. 3. The distribution device for map difference data according to 3. The control means, when comparing the searched first and second routes, determines whether or not each route is mutually the same in terms of position and shape, and determines whether or not a peripheral road along each route. Is also determined whether or not the locations and shapes are the same with respect to each other, and whether or not the locations and shapes of the various facilities and properties existing along each route are the same. 4. The map difference data distribution apparatus according to claim 3, wherein only the block-based map data corresponding to the difference portion is extracted based on a result of the determination. An in-vehicle navigation device communicably connected to a server equipped with the map difference data distribution device according to any one of claims 3 to 5,
A display device for providing guidance information to a user;
A rewritable storage medium storing map data necessary for navigation,
Position detection means for detecting the current position of the vehicle,
Information input means for inputting information necessary for searching for a destination or route;
The display device, a storage medium, a control means for controlling the input and output of the position detection means and information input means,
The control means transmits the position data and the user identification data to the server when a route search command is issued via the information input means,
When the map difference data is downloaded from the server, the map difference data is updated by overwriting the map data stored in the storage medium,
An in-vehicle navigation device comprising: searching for the second route based on the updated map data; and displaying the searched second route on a screen of the display device. When displaying the searched second route on the screen of the display device, the control means of the on-vehicle navigation device also includes the first route searched based on each position data transmitted to the server. The in-vehicle navigation device according to claim 6, wherein the navigation device is displayed on the display. The in-vehicle navigation device according to claim 7, wherein the control unit of the in-vehicle navigation device displays the first and second routes in different display modes on a screen of the display device. The control means of the in-vehicle navigation device causes the display device to divide a screen into two and display the first route on one screen and display the second route on the other screen. The in-vehicle navigation device according to claim 7, wherein: The in-vehicle navigation device according to claim 6, further comprising a memory unit that stores the user identification data.

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