JPH02136885A - Map data retrieving method - Google Patents

Abstract

PURPOSE:To immediately inform of the presence/absence of required map data by accumulating management information which indicates the presence/absence of map data at each level at every access of the map data or collectively storing in advance and discriminating the presence/absence of the required map data from the management information. CONSTITUTION:A map data managing section 9 accumulates management information which indicates the presence/absence of map data at each level to be expanded at each level about new map data whenever the new map data are retrieved and the storing address of a map data storing means 1 or collectively prepares and stores in advance the management information regarding the map data at each level. A system control CPU 7 discriminates the presence/ absence of required map data from the management information when the required map data are retrieved. Therefore, when the required map data exist, the map data are accessed based on the storing address and displayed on a map displaying section 11 and when the map data do not exist, it is immediately informed.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a map data search method for an automobile navigation system that searches for data (map data) essential for map display, and in particular, the present invention relates to a map data search method for an automobile navigation system that searches for data (map data) that is essential for map display. This invention relates to a map data search method that can instantly determine the presence or absence of map data.

<Prior art> Map data storage means storing map data, for example C
There is an automobile navigation system that uses D-ROM. Such an automobile navigation system stores a large amount of map data on a CD-ROM, and is also equipped with a display device, a position measuring device, etc. that measures the current position of the vehicle, and stores map data corresponding to the vehicle position on the CD-ROM. The location cursor is read from the ROM and drawn on the display screen, and a location cursor indicating the current position of the vehicle is drawn on the map, and the cursor is moved relative to the map as the vehicle moves.

<Problems to be Solved by the Invention> By the way, the map data stored on the CD-ROM has a hierarchical structure of several levels, ranging from wide range map data to detailed maps describing a predetermined area in detail. but,
Such map data does not store hierarchical map data for all areas, and some map data may be missing depending on the level of importance or area. Therefore, when reducing or enlarging a map, the required map data is stored on a CD.
- Check whether the CD-RO is actually in the ROM or not.
There is a problem in that it cannot be known unless M is accessed, and other processes in the system are put on hold due to this access time, resulting in a significant delay in a series of processes.

From the above, the purpose of the present invention is to determine the presence or absence of map data in each layer,
By accumulating management information indicating storage addresses, etc. each time map data is accessed, or by pre-determining and storing the management information in advance, the management information can be stored without directly accessing the CD-ROM, which has a slow processing speed. To provide a map data retrieval method capable of determining the presence or absence of required map data, immediately informing an operator of the presence or absence of map data, and accessing the map data at high speed.

<Means for Solving the Problems> In the present invention, the above problem is solved by providing management information indicating the presence or absence of hierarchical map data and the storage address, which is expanded to each layer regarding the map data every time new map data is searched. A means for accumulating or preliminarily creating and storing management information regarding map data in each layer; a means for determining the presence or absence of required map data based on the management information when searching for map data; If there is, this is achieved by means of accessing the map data based on the storage address included in the management information.

<Function> Every time new map data is searched, management information indicating the presence or absence of hierarchical map data and the storage address to be expanded to each layer regarding the map data is accumulated, or the map data in each Fa layer is stored in advance. When searching for map data, it is determined whether the required map data exists or not, and if map data is available, the map data is accessed based on the stored address. If there is no such information, it will be immediately notified.

<Example> Figure 1 shows an automobile navigation system that can realize the present invention.
FIG. 1 is a block configuration diagram of the system.

In the figure, 1 is a CD-R serving as a map data storage means.
It's OM. The map data stored on this CD-ROMI has a hierarchical structure of view sets A, B, and C. Here, viewsera I-A is map data for one screen at a certain standard scale, and view set B is map data for one screen for displaying an enlarged area of 1/4 of the area displayed in view set A. Set C is one screen worth of map data for enlarging and displaying a further 1/4 area of the area displayed in view set B, and each view set Ai,
The relationship between the ranges displayed on one screen by Bj and Ci is as shown in FIGS. 2(a) to (Q). In addition,
Focusing on view set A, (see Figure 2 (a)),
View set A-A4Δ6-A9 is View Cera 1-A
The adjacent map data of the area displayed by , B,
~B4 becomes enlarged map data. Also, view set B1
(See Figure 2(b)), view set A
5 is the reduced map data, c, , c2. c, , c6 become enlarged map data.

Returning to FIG. 1, reference numeral 2 denotes an operation unit equipped with various keys for accessing the CD-ROM, map search, etc., and 3 an azimuth sensor, which includes a geomagnetic sensor, a steering sensor, etc., and detects the absolute azimuth. Reference numeral 4 denotes a movement amount sensor, which includes a vehicle speed sensor that detects travel distance, a transmission sensor that detects forward and backward movement, and the like.

5 is a CPU for position calculation, and direction sensor 3. The current position of the vehicle is calculated based on the respective values inputted manually from the movement amount sensor 4. 6 is a processing unit, which includes a system control CPU 7, a map data buffer memory 8. Map data management section 9. CRT
It has a controller 10 and the like.

The system control CPU 7 receives the CD from the operation unit 2.
-Access the CD-ROMI and read out the necessary map data based on the ROM access command and the position of the own army manually input from the position calculation CPU 5.

Map data buffer memory 8 stores map data read from CD-ROM 1.

The map data management unit 9 indicates the presence or absence of layer-specific map data to be expanded to each layer regarding the map data each time a new viewcent (map data) is accessed, and if so, the storage address of the CD-ROMI, etc. Accumulate management information. In addition, the view set (map data) for each layer
It is also possible to create a configuration in which management information regarding the map is created in advance and stored in the map data management section 9.

The CRT controller I-roller 10 displays a desired map on a map display section 11 comprised of a liquid crystal, a cathode ray tube, or the like.

The map data stored in the map data buffer memory 8 will be explained below with reference to FIG. It is assumed that the vehicle currently exists in the area indicated by map data A.

When a map index indicating the current position of one's vehicle is input by key operation on the operation unit 2, or when a map index corresponding to the current position of the vehicle is determined, the system controller 7 reads data from the CD-ROMI according to the index. The map data A5 is read and stored in the map data buffer memory 8. This map data A, is input to the CRT controller 10 via the system controller 7, and the CRT controller 10 receives the map data A,
Based on this, a map is displayed on the display screen of the map display unit 11, and a cursor indicating the position of the own army is displayed based on the vehicle position calculated by the position calculation CPU 56.Then, as the vehicle moves, the cursor position is displayed. Move to display your army's position on the screen.

Thereafter, when the own army position moves to, for example, map data A, map data A to be BJIed from within, the system control CP tj 7 newly CT) map data A6) -
Read from ROMI, map data 8 sofa memory 8
to be memorized. Also, when a request is made to reduce or enlarge the map by key operation, the system control CPU
At 7, the reduced map data or enlarged map data including the location i4 where the own vehicle is present is newly read out from the CD-ROM 1, stored in the map data eight sofa memory 8, and displayed in the same manner.

As described above, the map data is read out each time the vehicle position moves from a predetermined map area to another area, or each time reduction/enlargement display is requested. However, map data A, ~A4.
A, ~A9 are read out in advance before the car approaches,
Map data A.

The screen of the map display section 11 may be configured to be instantly changed based on the map data A6 when the user moves from the inside to the map data A6.

By the way, view set A (standard scale map data) exists for all regions, but view set B (4x enlarged map data) and view set C (16x enlarged map data) are CD- It is not necessarily stored in ROM1.

Therefore, when a new view set (map data) is accessed, the hierarchical map data to be developed in each layer regarding the view set (map data), i.e. the presence or absence of enlargement map data B, C, etc., and the storage address, etc. Management information indicating this is accumulated and stored in the map data buffer memory 9.

In this way, when searching for map data, by referring to the management information of the map data management section 9, it is possible to immediately identify whether or not there is an adjacent or enlarged map to be targeted during the map search. As a result, for example, if there is no target map, it is possible to immediately notify ``No applicable map'', and instead of having to wait for access to the CD-ROMI to complete as in the past, ``No applicable map'' is notified. It is possible to eliminate operational problems such as having to access the site again. Furthermore, if a target map exists, the CD-ROMI can be accessed based on the storage address of the map to read and display the map data at high speed.

In addition, the management information is the adjacent map data A, ~A, A6~
A may also be created and stored.

FIG. 3 is an explanatory diagram of map data management information, which shows (i) whether or not CD-RCIMl is accessed, (ii) address in CD-ROMI where map data is stored, corresponding to each view set lJn. , (iii) The presence or absence of hierarchical map data, etc. are stored in the map data management unit 9. In addition, management information can be created and created in bulk by providing an initial setting process.
It may be configured to be memorized.

FIG. 4 is a flowchart of the process of the present invention.

First, when a request to display a map of a predetermined level where the vehicle is currently located is generated by key operation on the operation unit 2 or by movement (step 101), the CD-f
? , the OM controller/IzCPU 7 refers to the map data management section 9 (step 102) and checks whether there is management information regarding the map data of the requested level (for example, map data A5) (step 103); if there is no management information, The map data A is accessed (step 104), management information regarding the map data A is stored in the map data management unit 9 (step 105), and the CRT controller 1o is configured to access the map and the own army based on the map data A. Display the position on the map display section 11 (step 106)
, ends the process.

On the other hand, if there is management information as determined in step 103,
Based on the management information, it is determined whether or not the required map data A exists (Step 107), and if so, the CD
- Access the map data A5 in the ROMI (Step 108), and use the CRT controller 10 to display the position of your army on the map display section 11 based on the map data A5 (
Step 109).

Also, map data A is determined in step 107.

If there is no corresponding map, "No applicable map" is displayed on the map display unit 11 (step 110), and the process is terminated. In the above embodiment, a CD-ROM is used as an example of the map data storage means, but for example, a floppy disk, Automotive navigation system using cassettes etc. as map data storage means.
It is also possible to implement the invention in a system.

In addition, in the examples, the display screen is fixed.

Although the configuration in which the cursor is moved has been described, it is also possible to fix the cursor at the center of the screen and use scrolling to change the display area.

<Effects of the Invention> According to the present invention, whenever new map data is searched, management information indicating the presence or absence of layer-specific map data expanded to each layer regarding the map data is checked if 2 or collectively in advance. Management information regarding map data in each layer is created and stored, and when searching for map data, the presence or absence of required map data is determined based on the management information. Even without direct access, the presence or absence of required map data can be determined based on management information, and the user can immediately be notified of the presence or absence of map data.

Furthermore, since the management information is configured to include an address for storing map data, if map data is available, the data can be read out at high speed.

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of a navigation system for BaiflJtun that can realize the present invention, Fig. 2 is an explanatory diagram of the floor M structure of map data, Fig. 3 is an explanatory diagram of management information of map data, and Fig. 4 is a flowchart of the process of the present invention. 1...CD-ROM, 2...Operation unit. 3. Orientation sensor, 4. Movement amount sensor, 5. CPU for position calculation, 6. Processing device, 7. System control CPU, 8. Map data buffer 7 memory, 9. Map data management. Part 10... CRT controller.・Map display section.

Claims (2)

[Claims] (1) To display the current location of your vehicle on the screen,
In a map data search method for a car navigation system that searches for desired map data from map data stored in a map data storage means, each layer of map data is searched for each new map data each time new map data is searched. By accumulating management information indicating the presence or absence of map data for each layer to be developed, or by creating and storing the management information regarding map data in each layer in advance, when searching for map data, the management information A map data search method characterized by determining the presence or absence of map data. (2) If map data is present, its storage address is included in the management information, and the map data is accessed from the map data storage means based on the storage address. Map data search method described in Section 1.