JP4700128B2 - Map data provision system - Google Patents

Description

  The present invention belongs to the technical field of communication-type navigation devices, and particularly relates to pre-installation processing of map data performed at the initial setting of the navigation device.

  Conventionally, in navigation devices, map data stored in a map data recording medium such as a CD-ROM (Compact Disc-Read Only Memory) or a DVD-ROM (DVD-Read Only Memory) has been used. That is, the navigation apparatus includes a drive unit for a map data recording medium such as a CD-ROM or a DVD-ROM, reads map data near the current position of the vehicle from the map data recording medium in accordance with the movement of the vehicle, and It was displayed on a liquid crystal monitor attached nearby.

  However, when the map data supply source is such a recording medium, there arises a problem that the map data cannot be updated frequently. Map data is updated according to the development of a new road network such as an expressway. In addition to road data, the map data used in the navigation device includes information on nearby facilities and stores (for example, convenience stores and gas stations). Recently, there is a tendency that new stores are created relatively frequently or old stores are lost, so if you always want to get the latest information, you must frequently replace the map data recording medium. It will be a burden for me. In addition, since a new version of the map data recording medium is released every certain period, for example, half a year or one year, even if the latest version is purchased every time, it is often difficult to keep up with the actual store update.

  In addition, recently, with the enhancement of functionality of navigation devices, there is a tendency that data of incidental data other than road data included in map data is increased and complicated. For example, for performing advanced route search and route guidance It becomes necessary to install a microprocessor capable of high-speed processing in the navigation device. This leads to an increase in apparatus scale and cost.

  In order to solve such a problem, a communication type navigation system has been recently proposed. In this communication type navigation system, two-way wireless communication is used between a navigation device mounted on a vehicle and a map data providing center on a communication network, and map data is transferred from the map data providing center to the navigation device on the vehicle. Send. The navigation device stores the received map data on a storage medium such as a hard disk, and performs map display, route guidance, etc. using the map data. Examples of such communication-type navigation devices are described in Patent Documents 1 and 2, for example.

  According to such a communication type navigation system, if the map database on the map data providing center side is updated, the user can always use the latest map data by communication.

JP-A-7-262495 Japanese Patent Laid-Open No. 10-96644

  However, communication costs are incurred when communicating with the map data providing center to acquire map data, which is usually a burden on the user side. Therefore, if all the map data used by the user in the communication type navigation device is acquired by communication, the cost may be a considerable burden on the user.

  It is an object of the present invention to provide a method for efficiently installing map data in a necessary range for each user in the navigation device in the communication type navigation device as described above.

In one aspect of the present invention, in a map data providing system including a terminal device and a map data providing center that provides map data to the terminal device, the terminal device is a reference that is a reference for the range of the map data A terminal-side transmitting unit that transmits point information to the map data providing center, a terminal-side receiving unit that receives the map data from the map data providing center, and the map data received by the terminal-side receiving unit are stored. Storage means, and the map data providing center includes a center side receiving means for receiving the reference point information from the terminal device, and a plurality of meshes in a predetermined region centered on the mesh including the reference points. The selection means to select, and the road selected as the provision target to the terminal device in the mesh for the mesh selected by the selection means Determination means for determining whether or not data is included, and center-side transmission means for transmitting mesh data including the road data to be provided to the terminal device as the map data, and the selection means includes: A mesh adjacent to the predetermined region is selected according to a determination result of the determination unit for the plurality of meshes.

In one aspect of the map data providing system, when the determining unit determines that the road data to be provided is not included in the mesh, the selecting unit replaces the mesh with the predetermined data. Select the mesh adjacent to the region.

  As described above, according to the present invention, necessary map data can be efficiently preinstalled for each user.

It is a figure which shows typically the utilization condition of the communication type navigation apparatus concerning embodiment of this invention. It is a block diagram which shows the structure of the communication type navigation apparatus shown in FIG. 1 schematically shows a configuration of a system for executing preinstallation processing. A state where an area is divided into a plurality of meshes is schematically shown. The structure of map data (mesh data) is shown. It is a flowchart of the 1st pre-installation method. An example of determining preinstalled mesh data is shown. It is a flowchart of the 2nd pre-installation method. It is a figure explaining the selection order of the mesh in the 2nd pre-installation method.

  In the communication type navigation device, the map data is basically acquired by communication. However, when the device is introduced, it is necessary to prepare a relatively large amount of data. The burden of communication costs increases. Therefore, in the present invention, a certain amount of basic map data is first stored in advance in a map data storage medium on the apparatus side (hereinafter, this process is also referred to as “pre-installation”), and thereafter as necessary. Then, an efficient method of acquiring necessary map data by connecting to the map data providing center is adopted.

  Preferred embodiments of the present invention will be described below with reference to the drawings. The following description shows an example in which the present invention is applied to a communication navigation device for vehicles (hereinafter simply referred to as “navigation device”).

[1] Navigation Device FIG. 1 schematically shows the usage status of a navigation device according to an embodiment of the present invention. In FIG. 1, the navigation device 7 is mounted on a vehicle 5. The navigation device 7 measures the position of the vehicle by receiving radio waves from the plurality of satellites 4. The navigation device 7 connects to the map data providing center 6 using a communication function, downloads the map data, and stores it in the internal map data storage unit. By acquiring necessary map data from the map data providing center 6 as the vehicle advances, functions such as route guidance and route guidance can be executed.

  FIG. 2 shows the configuration of the navigation device 7. As shown in FIG. 2, the navigation device 7 includes a self-supporting positioning device 10, a GPS receiver 18, a system controller 20, a CD-ROM drive 31, a DVD-ROM drive 32, a data storage unit 36, a communication interface 37, and a communication device. 38, a display unit 40, an audio output unit 50, and an input device 60.

  The self-supporting positioning device 10 includes an acceleration sensor 11, an angular velocity sensor 12, and a distance sensor 13. The acceleration sensor 11 is made of, for example, a piezoelectric element, detects vehicle acceleration, and outputs acceleration data. The angular velocity sensor 12 is composed of, for example, a vibrating gyroscope, detects the angular velocity of the vehicle when the direction of the vehicle is changed, and outputs angular velocity data and relative orientation data.

  The distance sensor 13 measures a vehicle speed pulse that is a pulse signal generated with the rotation of the vehicle wheel.

  The GPS receiver 18 receives a radio wave 19 that carries downlink data including positioning data from a plurality of GPS satellites to be used for detecting the absolute position of the vehicle from latitude and longitude information. It is.

  The system controller 20 includes an interface 21, a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 23, and a RAM (Random Access Memory) 24, and is configured to control the entire navigation device 7. .

  The interface 21 performs an interface operation with the acceleration sensor 11, the angular velocity sensor 12, the distance sensor 13, and the GPS receiver 18. From these, acceleration data, relative azimuth data, angular velocity data, GPS positioning data, absolute azimuth data and the like are input to the system controller 20 in addition to the vehicle speed pulse. The CPU 22 controls the entire system controller 20. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22.

  The system controller 20, the CD-ROM drive 31, the DVD-ROM drive 32, the data storage unit 36, the communication interface 37, the display unit 40, the audio output unit 50 and the input device 60 are connected to each other via the bus line 30. ing.

  The CD-ROM drive 31 and the DVD-ROM drive 32 read out and output content data such as music data and video data and control programs corresponding to each processing described later from the CD 33 and DVD 34 under the control of the system controller 20, respectively. To do. Note that either one of the CD-ROM drive 31 and the DVD-ROM drive 32 may be provided, or a CD and DVD compatible drive may be provided.

  In the present invention, the map data used in principle is pre-installed as described later or acquired from the map data providing center 6 by communication. However, the map data stored in the CD-ROM 33 and the DVD-ROM 34 are used. The data can be read and used. In particular, when using discs of special projects other than general map data (for example, golf course maps, ski resort maps, sightseeing tour guides, etc.), CD-ROM drive 31 or DVD-ROM The drive 32 can be preferably used.

  The data storage unit 36 is a unit that mainly stores map data. The map data is acquired by a pre-installation process described later, and is acquired from the map data providing center 6 as necessary while the vehicle is running and stored in the data storage unit 36. The data storage unit 36 can also store audio data and video data read from the CD-ROM drive 31 or the DVD-ROM drive 32 and map data of the above-mentioned disc of the project as necessary. .

  The communication device 38 is composed of, for example, a mobile phone, and is configured so that map data can be downloaded from the map data providing center 6 via a communication interface 37 constituting a modem or the like.

  The display unit 40 displays various display data under the control of the system controller 20. The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30 and image information that can be displayed immediately, such as a VRAM (Video RAM). A buffer memory 42 that temporarily stores, a display control unit 43 that controls display of a display 44 such as a liquid crystal display or a CRT (Cathode Ray Tube) based on image data output from the graphic controller 41, and a display 44 are provided. Configured. The display 44 is composed of, for example, a liquid crystal display device having a diagonal of about 5 to 10 inches, and is mounted near the front panel in the vehicle.

  The audio output unit 50 performs D / A (Digital to Analog) conversion of audio digital data sent from the CD-ROM drive 31, DVD-ROM 32, RAM 24, or the like via the bus line 30 under the control of the system controller 20. A D / A converter 51 to perform, an amplifier (AMP) 52 that amplifies the audio analog signal output from the D / A converter 51, and a speaker 53 that converts the amplified audio analog signal into sound and outputs the sound into the vehicle. It is prepared for.

  The input device 60 includes keys, switches, buttons, a remote controller, a voice input device, and the like for inputting various commands and data. The input device 60 is disposed around the front panel and the display 44 of the main body of the in-vehicle electronic system mounted in the vehicle.

[2] Pre-installation system Next, a system for pre-installing map data will be described. In principle, map data is acquired from the map data providing center 6 by communication in the communication type navigation device 7 of the present invention. However, when the navigation device 7 is introduced, for example, a region that will be used relatively frequently such as near the home. Pre-install map data. This eliminates the need to download a large amount of map data by communication when the navigation device 7 starts to be used.

  FIG. 3 schematically shows the configuration of a system for executing the preinstall process. As shown in FIG. 3, the store 8 and the map data providing center 6 are connected via a communication network 103. The sales store 8 is a navigation system sales store, for example, a car dealer or a car supplies store.

  The map data providing center 6 includes a map server 101 and a map database (hereinafter referred to as “DB”) 104. The map DB 104 stores map data. In response to a request from the store 8, the map server 101 acquires necessary map data from the map DB 104 and transmits it to the store 8 through the communication network 103.

  In the store 8, a preinstall terminal 102 connected to the communication network 103 is installed. The preinstalled terminal 102 transmits a request for map data to be preinstalled in the user's navigation device 7 to the map data providing center 6, receives the corresponding map data, and temporarily stores it in an internal memory or the like. Then, the map data is stored in the data storage unit 36 of the navigation device 7.

  There are several methods for storing map data from the pre-installed terminal 102 to the data storage unit 36 of the navigation device 7. One method is that the preinstall terminal 102 temporarily stores map data in a storage medium such as a DVD-RAM, a semiconductor memory, or a card-type storage medium, and inserts it into the drive device of the navigation device 7 to insert the data storage unit. 36.

  In addition, when the data storage unit 36 is configured by a removable medium such as a semiconductor memory or a hard disk, the map data is stored in such a medium from the preinstalled terminal 102 and then the medium is provided to the user. You can also. The user simply installs the medium in his / her navigation device 7 and the pre-installation of the map data is completed. In addition, according to this method, it is possible to eliminate the need for the user to visit the store 8 for pre-installation by providing the user with a storage medium storing the pre-install map data by means such as mail. It becomes. In addition, map data is stored in the data storage unit 36 by using the communication function of the navigation device 7 to wirelessly communicate with the preinstalled terminal 102 by, for example, infrared rays, or by connecting data lines to perform data communication. Can do.

[3] Map Data Next, the structure of map data will be described. The map data is created in units obtained by dividing a predetermined geographical area into a plurality of sections having a predetermined area. This unit is called “mesh”, and the map data corresponding to one mesh is called “mesh data”. Therefore, the map data is a set of mesh data.

  FIG. 4 schematically shows a state where a map of an area along the sea is divided into a plurality of meshes. In FIG. 4, a line 111 indicates a coastline, the right side of which is a water area (sea) and the left side is land. The upper left area in FIG. 4 is a mountain. A line 110 indicates a road.

  This area is divided into a plurality of meshes M defined in a grid pattern as map data. In FIG. 4, the identification numbers (M11 to M55) are shown inside each mesh M. The mesh data is prepared for each mesh shown in FIG. The x and y coordinates in FIG. 4 correspond to longitude and latitude, respectively.

  Further, the map shown in FIG. 4 is of a specific scale, and mesh data is created for each of a plurality of scales. The map of Japan has been created in a plurality of scales, but the map is divided into a plurality of meshes for each scale, and mesh data is prepared.

  FIG. 5 shows the contents of the mesh data. The mesh data roughly includes road data, background data, and annotation data. The road data is vector data indicating roads on the map. The background data is data indicating other than roads in the area displayed as a map. In the map displayed on the navigation device 7, the state in the vicinity of the road is shown in addition to the road. For example, if there is a pond along the road, an image showing the pond is displayed, and if it is a city map, a geographical section is displayed. These are included as background data.

  The annotation data is data corresponding to characters, symbols, marks, etc. displayed on the map, and includes character data, facility map signs, and logo marks. In the map displayed by the navigation device, place names, addresses, intersection names, station names, and the like are displayed in characters. Character data is data of these characters. On the map, for example, facilities such as schools, hospitals, and post offices may be displayed as map symbols, and these are included in the data indicating the facility's map sign. Further, marks indicating stores such as convenience stores and gas stations are displayed, and these logo marks are also included in the note data.

  As described above, the mesh data basically includes road data, background data, and annotation data. However, each data may not exist depending on the area to which the mesh corresponds. For example, the mesh M55 shown in FIG. 4 is a completely sea area, and there are no roads, facilities, stores, or the like. Therefore, the mesh data of the mesh M55 does not include road data and annotation data, but includes only background data. In the case of the mesh M55, since the entire area is displayed in blue indicating that it is the sea as the map display, only background data for that is included.

  As understood from this, the data amount of each mesh data is different for each mesh. For example, meshes M43 and M34 in FIG. 4 include a plurality of roads and further include a coastline, so that the amount of data included in the mesh data is large. On the other hand, the mesh data M55, which is a completely sea area, and the mesh M11, which is a completely mountain area (no road), has a small amount of mesh data.

  As described above, since the map data is created as a plurality of mesh data for each scale, the preinstall process is also performed in units of mesh data. That is, pre-installation is performed by storing a plurality of mesh data in the data storage unit 36 of the navigation device 7.

[4] First Preinstallation Method Next, an example of a specific preinstallation process will be described with reference to FIG. 3, FIG. 4, and FIG. FIG. 6 is a flowchart showing the first pre-installation method. In the following example, in the system shown in FIG. 3, the user who purchased the navigation device 7 visits the store 8, and the store clerk obtains necessary information from the user and operates the preinstall terminal 102 to perform preinstall processing. Shall be executed.

  The preinstall terminal 102 can be a terminal device such as a personal computer having a communication function via a communication network, and operates as a preinstall terminal by executing a preinstall program. Similarly, the map server 101 also performs a preinstall process by executing a preinstall program that executes the steps described below.

  First, the store clerk operates the preinstalled terminal 102 to input a reference point designated by the user (step S1). Here, the “reference point” refers to a geographical location serving as a reference for determining the range of map data to be preinstalled. The reference point can be an arbitrary location desired by the user, and usually the user often sets a home, work place, etc. where the vehicle is frequently used as a reference point. As a reference point input method, for example, a store clerk can input an address designated by the user as a reference point in a preinstall program.

  The reference point information set in this way is transmitted to the map data providing center 6 through the communication network 103. The map server 101 of the map data providing center 6 selects a predetermined number D of meshes by a predetermined method based on the reference point, and temporarily stores it in a memory (not shown) in the map server 101 (step S2). .

  The predetermined number D of meshes to be selected here can be determined based on the size of a storage area that can be secured for preinstalled map data in the data storage unit 36 of the navigation device 7, for example. That is, if the storage area for preinstalled map data has a storage capacity X and the average data amount of one mesh is Y, it can be determined that the predetermined number D = X / Y.

  Further, as another method of determining the predetermined number D, for example, an area where the user will act on a daily basis or relatively frequently from a reference point (usually at home or the like) is statistically examined, and that area is included. Thus, an area to be preinstalled can be determined, and the number of meshes covering the area can be set to the predetermined number D. If there is statistical data that the range in which the user behaves on a daily basis is, for example, a radius of about 20 km from home or work, the number of meshes can be determined so as to cover the area.

  In addition, as a method for selecting a mesh, for example, a rectangular or circular area centered on a mesh including a reference point is assumed, and the mesh can be selected to be rectangular or circular within the predetermined number of ranges. Note that these are merely examples, and it is needless to say that the number of meshes and the selection method can be determined by other methods.

  Now, when a predetermined number of meshes are selected based on the reference points in this way, the map server 101 next detects unnecessary meshes in the selected mesh (step S3). Here, the unnecessary mesh is a mesh determined to be unnecessary (not used in route guidance or search) in the navigation device 7, and basically determines an unnecessary mesh based on whether road data is included. be able to. In the example of FIG. 4, for example, mesh data M11 and M21 in a forest area where no road exists, and mesh data M54 and M55 in which only a water area (sea) exists (not including land) are handled as unnecessary meshes. it can.

  In this way, if the unnecessary mesh is determined as a mesh that does not include road data, for example, the map server 101 checks whether or not road data is included for each of the predetermined number of meshes selected in step S2. Meshes can be detected.

  Then, the map server 101 replaces the detected unnecessary mesh with another mesh (step S4). As a method for determining a mesh to be replaced, for example, a mesh in a direction opposite to the detected unnecessary mesh can be selected on the basis of the mesh including the reference point. This is most commonly assumed as unnecessary mesh in water areas such as forests and seas, and when such an unnecessary mesh is detected, the direction opposite to the reference point corresponding to the home or work place, etc. Is based on the assumption that it is not likely to be a forest or water area as well. As another method, it is possible to sequentially select meshes adjacent to the already selected mesh.

  When the unnecessary mesh is replaced with another mesh in step S4, it is determined whether or not the unnecessary mesh no longer exists in all the meshes selected in step S2 (step S5).

  Therefore, all unnecessary meshes included in the predetermined number of meshes selected in step S2 are replaced by steps S3 to S5. Note that when a mesh detected as an unnecessary mesh is replaced with another mesh, the replaced mesh may be an unnecessary mesh, but even in that case, it is detected again as an unnecessary mesh and replaced in step S3. Therefore, when the determination result in step S5 finally becomes affirmative (Yes), all the predetermined number of meshes should be no longer unnecessary meshes.

  Thus, when the unnecessary mesh is not included in the predetermined number of meshes, the map server 101 transmits mesh data of these meshes to the preinstall terminal 102 via the communication network 103 (step S6).

  The preinstall terminal 102 receives the mesh data (step S7) and installs it in the data storage unit 36 of the navigation device 7 (step S8). As described above, various methods can be used for the installation. Thus, preinstallation is completed.

  Next, a specific example of the above preinstall process will be described with reference to FIG. Now, it is assumed that the user of the navigation apparatus 7 performing preinstallation sets a point 130 shown in FIG. 4 as a reference point as a reference point. If it is determined in step S2 that, for example, nine meshes composed of three vertical and horizontal meshes centered on the mesh including the reference point are selected, meshes M23 to M25, M33 to M35, and M43 are selected in step S2. ~ M45 is selected. Here, the meshes M35 and M45 are meshes that completely hit the water area, detected as unnecessary meshes in step S3, and replaced with other meshes in step S4. For example, if the mesh including the reference point is replaced with a mesh located in the opposite direction of the unnecessary mesh with the reference as a reference, for example, the meshes M35 and M45 are replaced with the meshes M22 and M32 in step S4.

  Thus, when it is determined in step S5 whether or not the unnecessary mesh has disappeared, it is understood that the mesh M22 replaced in step S4 is a mesh in an area where there is no road in the forest area, and this is also an unnecessary mesh. Therefore, steps S3 to S5 are repeated, and in step S4, for example, mesh M42 in the opposite direction to the first unnecessary meshes M35 and M45 with the mesh including the reference point as a reference is replaced with mesh M22. Thus, in step S5, a predetermined number of meshes not including unnecessary meshes are prepared. As a result, the mesh data finally preinstalled in the user's navigation device 7 is meshes M23 to M25, M32 to M34, and M42 to M44 as shown in FIG. 7, and includes unnecessary meshes such as forest areas and water areas. It will not be.

  Thus, according to the pre-installation processing of the present invention, map data within a predetermined range centered on the reference point selected by the user, and does not include unnecessary meshes such as forest areas and water areas. Is preinstalled. Since the amount of map data that can be pre-installed is limited by the storage capacity of the data storage unit 36 of the navigation device 7, it is possible to efficiently pre-install only valid map data by the above-described processing.

[5] Second Preinstallation Method Next, another example of the preinstallation process will be described with reference to FIGS. FIG. 8 is a flowchart of the second pre-installation method, and FIG. 9 is a diagram schematically showing the method.

  In the above example, when a reference point is set, a predetermined number of meshes are first selected, and unnecessary meshes included therein are replaced with valid meshes. On the other hand, the method described below is a method in which when a reference point is set, meshes are acquired one by one while determining whether or not the mesh is an unnecessary mesh based on the reference point.

  In FIG. 8, as in the first pre-installation method, when a reference point is set by the user (step S11), the reference point data is transmitted to the map data providing center 6, and the map server 101 is based on the reference point. One mesh is selected (step S12). An example of a method of selecting meshes one by one is shown in FIG. In the example of FIG. 9, the meshes are selected clockwise in order around the mesh to which the reference point 130 belongs (see selection order 120). Then, it is determined whether or not the selected mesh is an unnecessary mesh (step S13). If the selected mesh is an unnecessary mesh, the next mesh is selected according to the selection order 120 (step S14), and the process returns to step S13 to return to the mesh. Is determined to be an unnecessary mesh.

  If it is determined in step S13 that the mesh is not an unnecessary mesh, the map server 101 acquires mesh data of the mesh from the map DB 104 (step S15), and determines whether a predetermined number of meshes have been acquired (step S16). If the predetermined number of meshes has not been acquired, the process returns to step S12 to acquire the next one mesh, and the same process is repeated.

  Thus, when a predetermined number of meshes not including unnecessary meshes are acquired (step S16; Yes), the map server 101 transmits mesh data of these meshes to the preinstall terminal 102 of the store 8 (step S17). The dealer 8 receives the mesh data (step S18) and stores it in the data storage unit 36 of the navigation device 7 in the same manner as in the above example.

  As a result, the mesh data thus obtained is the same as in the case of the first preinstall method as shown in FIG. Therefore, the user can pre-install effective mesh map data based on the reference point designated by the user.

[6] Modification In the above example, the map data of a predetermined number of meshes is acquired based on the reference points. Instead, the number of map data to be acquired is determined by the distance from the reference points. It can also be determined.

  In addition, for example, in a water area such as meshes M45 and M55 in FIG. 4 and a forest area such as mesh M11, substantial mesh data may not be prepared from the beginning. Even in that case, information indicating that corresponding mesh data does not exist for the mesh should be stored in the map DB 104. Therefore, in the first and second pre-installation methods, the existence of such mesh data exists. What is necessary is just to treat the mesh which does not carry out equivalent to an unnecessary mesh, and to replace with another mesh.

  The above embodiment is a case where the present invention is applied to a vehicle navigation device. However, the present invention is not limited to this, and can be applied to a communication type navigation device for other moving bodies such as ships and airplanes. Is possible. Further, the present invention can be applied to a portable navigation device carried by a human.

4 Satellite 5 Vehicle 6 Map data providing center 7 Communication type navigation device 10 Autonomous positioning device 18 GPS receiver 20 System controller 31 CD-ROM drive 32 DVD-ROM drive 36 Data storage unit 37 Communication interface 38 Communication device 40 Display unit 50 Audio output unit 60 Input device 101 Map server 102 Preinstalled terminal 103 Communication network 104 Map database

Claims (2)

In a map data providing system comprising a terminal device and a map data providing center that provides map data to the terminal device,
The terminal device
Terminal-side transmission means for transmitting information of a reference point serving as a reference of the range of the map data to the map data providing center;
Terminal-side receiving means for receiving the map data from the map data providing center;
Storage means for storing the map data received by the terminal-side receiving means,
The map data providing center
Center-side receiving means for receiving information on the reference point from the terminal device;
Selecting means for selecting a plurality of meshes in a predetermined region centered on the mesh including the reference point;
Determining means for determining whether the mesh selected by the selecting means includes road data to be provided to the terminal device in the mesh;
Center side transmission means for transmitting mesh data including the road data to be provided to the terminal device as the map data,
The map data providing system, wherein the selection unit selects a mesh adjacent to the predetermined region in accordance with a determination result of the determination unit for the plurality of meshes.   The selection unit selects a mesh adjacent to the predetermined region instead of the mesh when the determination unit determines that the road data to be provided is not included in the mesh. The map data providing system according to claim 1.

Images