Patent Grant
7440849
Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 2003-0072854, filed on Oct. 20, 2003, the contents of which are hereby incorporated by reference herein in their entirety.
1. Field of the Invention
The present invention relates to a method for managing map data for a vehicle, wherein upon display of map data on a display unit by using a navigation system, memory loading for the display of the map data can be quickly performed by reducing the number of access to a physical storage medium with an entire map stored therein.
2. Description of the Related Art
Generally, a navigation system provides functions of calculating a current location of a traveling vehicle using radio signals transmitted by a plurality of satellites belonging to a global positioning system and signals transmitted by sensors of the vehicle, and guiding the vehicle along an optimum path from a starting place to a destination by map-matching the calculated position to map data.
Particularly, in a full navigation system for guiding a vehicle along a path by displaying the path as well as the position of the vehicle, loading of a nationwide map and relevant map data is inevitably required in order to search for a path, guide a travel and visualize a map.
However, due to a large amount of map data and limitations on hardware, it is practically impossible to load such map data on a screen memory. This will be described in detail by way of example with reference to
However, in such a conventional map data management, map data of a new area should be continuously loaded from a physical storage medium such as a CD-ROM as a vehicle travels. Time required for loading the map data from the physical storage medium causes a considerable delay upon display of a travel guide map for the vehicle.
Therefore, to avoid the time delay of the display, there is a need for improving speed at which the travel guide map is displayed, by minimizing access overhead through reduction in the number of access to the physical storage medium.
Accordingly, the present invention is conceived to meet the aforementioned need. An object of the present invention is to provide a method for managing map data for a vehicle, wherein upon display of the map data, memory loading for the display of the map data can be quickly performed by reducing the number of access to a physical storage medium with an entire map stored therein.
In the present invention for achieving the above object, when a travel guide map is generated again based on a new location as the position of a vehicle varies, only a certain number of map segments are retrieved from a physical storage medium such as a CD-ROM or hard disk to generate the travel guide map, thereby making map-displaying speed faster.
Further, when the travel guide map is generated again based on the new location as the position of the vehicle varies, map data loading speed can be faster by preventing reusable map segments among map segments loaded on an operation memory from being unnecessarily deleted, retrieved again from the physical storage medium and inserted into the operation memory.
Moreover, when the travel guide map is generated again based on the new location as the position of the vehicle varies, a certain number of necessary map segments are detected and updated into the operation memory so that the updated map segments can be retrieved from the operation memory and then loaded on a screen memory, thereby making map data loading speed faster.
The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First to third embodiments of the present invention will be sequentially described in connection with a navigation system shown in
As shown in
The term “map segment” used herein is defined as partial map data obtained by uniformly dividing a certain entire map into segments with a predetermined size based on latitude and longitude. Respective map segments are identified by identification numbers.
The first embodiment of the present invention will be described below in connection with the navigations system described above.
In the first embodiment of the present invention, when a travel guide map is generated again based on a new location as the position of a vehicle varies, only a certain number of map segments are retrieved from a physical storage medium such as a CD-ROM or hard disk to generate the travel guide map, thereby making map-displaying speed faster.
To this end, in the first embodiment of the present invention, map segments usable for displaying a travel guide map based on a current vehicle location are selected among a predetermined number of map segments that have been loaded in the operation memory 200 to display a travel guide map based on a previous location.
That is, in the first embodiment of the present invention, when the GPS receiver 100 receives GPS data and calculates coordinates of a current vehicle location, a central map segment including the calculated coordinates of the location and a predetermined number of adjacent map segments surrounding the central map segment are detected to display a map with a predetermined size on the display panel.
Then, map segments identical with the detected central map segment and the adjacent map segments are selected, as map segments usable for displaying a travel guide map based on a current vehicle location, among the predetermined number of map segments that have been loaded in the operation memory 200 to display the travel guide map based on the previous location.
At this time, it is preferred that the adjacent map segments be sequentially detected according to the degree of proximity to the central map segment, and an entire map divided into map segments with a predetermined size based on latitude and longitude be used.
Meanwhile, the map segments selected as being usable for displaying the travel guide map based on the current vehicle location are designated as properties, and remaining map segments are designated as victims.
At this time, it is preferred that predetermined different marks be assigned to the respective map segments designated as properties and victims so as to identify them. For example, it is preferred that a binary bit flag of “1” be assigned to the properties, while a binary bit flag of “0” be assigned to the victims. The marks are initialized whenever the position of the vehicle varies.
In the first embodiment of the present invention, as for the map segments designated as the properties, they are reinserted into the operation memory 200 even though they have been deleted from the operation memory 200 in a predetermined order, e.g., in a first-in first-out (FIFO) manner. For example, the map segments designated as the properties are deleted at their turns in the FIFO manner. The deleted map segments are added to an insertion queue, and the map segments added to the insertion queue are reinserted into the operation memory 200 in a relevant order.
Then, the map segments designated as the victims are completely deleted from the operation memory 200, and remaining map segments required for displaying the travel guide map based on the current vehicle location are retrieved from the physical storage medium 120 with the entire map stored therein and are then updated into the operation memory 200. At this time, the map segments designated as the victims are deleted from the operation memory 200 in the practicable FIFO manner, and the map segments retrieved from the physical storage medium 120 are inserted into the operation memory 200.
The map segments updated into the operation memory in such a manner, and the map segments designated in advance as the properties are loaded on a screen memory.
As a result, according to the first embodiment of the present invention, when a travel guide map is generated again based on a new location as the position of the vehicle varies, only a certain number of map segments are retrieved from the physical storage medium such as a CD-ROM or hard disk to generate the travel guide map, thereby making map-displaying speed faster.
Next, the second embodiment of the present invention will be described with reference to
The second embodiment of the present invention is to further specify the operation memory managing mechanism described above.
In the second embodiment of the present invention, when the position of the vehicle varies in a state where a predetermined number of map segments have been loaded on the operation memory to display a travel guide map based on a previous location on the display unit, map segments reusable for displaying a travel guide map based on a new location are selected among the map segments loaded on the operation memory.
Then, the selected map segments are designated as properties, and remaining map segments are designated as victims.
In the second embodiment of the present invention, it is then determined whether the operation memory 200 is full. If it is determined that the operation memory 200 is not full, remaining map segments required for displaying a travel guide map based on a current vehicle location are retrieved from the physical storage medium with the entire map stored therein and are then updated into the operation memory.
On the contrary, if it is determined that the operation memory is full, the map segments which have been previously loaded on the operation memory 200 are sequentially deleted one by one in order to fill the interior of the operation memory 200 with map segments usable for displaying the travel guide map based on the current vehicle location.
Then, it is determined whether the deleted map segments are those designated as properties or victims.
If it is determined that the deleted map segments are those designated as properties, they are reinserted into the operation memory. If it is determined that the deleted map segments are those designated as victims, they are completely deleted from the operation memory. Thereafter, remaining map segments required for displaying the travel guide map based on the current vehicle location on the display unit are sequentially retrieved from the physical storage medium with the entire map stored therein and then are updated into the operation memory.
Here, it is preferred that predetermined different marks be assigned to the respective map segments designated as properties and victims so as to identify them, and the marks be initialized whenever the position of the vehicle varies.
According to the second embodiment of the present invention, when the travel guide map is generated again based on the new location as the position of the vehicle varies, map data loading speed can be faster by preventing reusable map segments among the map segments loaded on the operation memory from being unnecessarily deleted, retrieved again from the physical storage medium and inserted into the operation memory.
Next, the third embodiment of the present invention will be described with reference to
In the third embodiment of the present invention, the speed of loading map data on the screen memory, which has been required for displaying a travel guide map on the display unit, becomes faster by loading the map data of the travel guide map on the screen memory while minimizing the number of access to the physical storage medium such as a CD-ROM or hard disk.
To this end, in the third embodiment of the present invention, a certain number of map segments required for generating a travel guide map based on a new location are updated into the operation memory 200 as the position of the vehicle varies.
More specifically, a position information extracting section of the control unit 150 first calculates coordinates of a current vehicle location using GPS data received by the GPS receiver 100. Then, a map segment including the coordinates of the current vehicle location, and a predetermined number of adjacent map segments surrounding the map segment are detected.
Subsequently, the memory manager 210 searches the operation memory 200 under the control of the control unit 150, selects map segments identical with the map segments, which have been detected by the position information extracting section, among map segments stored in the operation memory 200, and deletes remaining map segments except the selected map segments from the operation memory 200.
Thereafter, remaining map segments required for generating the travel guide map based on the new location are retrieved from the physical storage medium with the entire map stored therein and are then updated into empty areas of the operation memory which are obtained by deleting the remaining map segments except the selected map segments.
Finally, the control unit 150 accesses to the operation memory 200 instead of the physical storage medium 120 with the entire map stored therein in response to a display request input from the outside, and loads the map segments updated into the operation memory 200 on the screen memory (not shown), thereby displaying the travel guide map on the display unit 140 using the map segments loaded on the screen memory as described above.
According to the third embodiment of the present invention, the map data loading speed becomes faster in such a manner that the certain number of map segments required for generating the travel guide map based on the new location as the position of the vehicle varies are detected and then updated into the operation memory, and the updated map segments are retrieved from the operation memory and then loaded on the screen memory.
Next, the operation memory 200 in the present invention will be described in greater detail with reference to
In the present invention, a predetermined number of map segments required for displaying a travel guide map based on the position of a vehicle on the display unit are loaded on the operation memory. When the position of the vehicle varies, it is determined whether there are map segments usable for displaying a travel guide map based on a new location on the display unit, among the map segments loaded on the operation memory. Relevant usable map segments are selected and designated as properties and remaining map segments are designated as victims.
At this time, it is preferred that the map segments designated as the properties and victims be distinguishable from each other. To this end, it is preferred that, for example, a binary bit flag of “1” be assigned to the properties and a binary bit flag of “0” be assigned to the victims, as shown in the figure. The marks are initialized whenever the position of the vehicle varies.
To fill the interior of the operation memory 200 with the map segments usable for displaying the travel guide map based on the current vehicle location on the display unit, the map segments that have been previously loaded on the operation memory are sequentially deleted one by one.
At this time, if the deleted map segments are those designated as the properties, they are reinserted into the operation memory. If deleted map segments are those designated as the victims, they are completely deleted from the operation memory. Thereafter, remaining map segments required for displaying the travel guide map based on the new location on the display unit are sequentially retrieved from the physical storage medium with the entire map stored therein and are then updated into empty areas of the operation memory which are obtained by deleting the map segments.
As a result, the map data loading speed can be improved by lowering the possibility that latest data will be selected as victims and preventing deletion of data usable for displaying a travel guide map.
Next, the operation memory managing mechanism of the present invention will be described in greater detail with reference to
In the operation memory managing mechanism of the present invention, map segments usable for displaying a travel guide map based on a current vehicle location on the display unit are selected among a predetermined number of map segments that have been loaded on the operation memory to display a travel guide map based on a previous location on the display unit, and the selected map segments are designated as properties and remaining map segments are designated as victims.
Then, to fill the operation memory with the map segments required for displaying the travel guide map based on the current vehicle location on the display unit, the map segments that have been loaded on the operation memory are sequentially deleted one by one.
At this time, it is determined whether the deleted map segments are those designated as properties or victims. If it is determined that the deleted map segments are those designated as the properties, they are reinserted into the operation memory.
For example, in a case where the operation memory is a cache memory managed through queues in the FIFO manner as shown in
As a result, map segment 22294 positioned at the front is deleted. However, since map segment 22294 is a map segment designated as a property with a flag of “1”, it is reinserted into the rear even after the deletion thereof. In order to reinsert map segment 22294, map segment 18310 positioned at the front is deleted. At this time, since map segment 18310 is a map segment designated as a victim with a flag of “0”, it is not reinserted into but completely deleted from the cache memory. Such processes are repeated until all map segments with the flag of “0” are deleted. If an empty area is produced in the cache memory, a map segment designated as a victim is reinserted into the cache memory, or data on a new map segment, i.e. a map segment usable for displaying the travel guide map based on the current vehicle location on the display unit, are retrieved from the physical storage medium and then inserted into the cache memory.
Accordingly, the present invention allows the operation memory such as a cache memory to be filled with the map segments required for displaying the travel guide map based on the current vehicle location on the display unit as the position of the vehicle varies.
Next, the operation memory managing mechanism of the present invention will be described by way of example with reference to
In the operation memory managing mechanism of the present invention shown in
As shown in
Thereafter, to fill the operation memory with map segments required for displaying the travel guide map based on current position (2) on the display unit, the map segments that have been loaded on the operation memory are sequentially deleted one by one.
At this time, since the mark for identifying the property has been assigned to map segments 18311 and 18310, map segments 18311 and 18310 are reinserted even though they have been deleted at their turns. Only new map segments 16793 and 16794 that have not been loaded on the operation memory are retrieved from the physical storage medium and newly inserted into the operation memory. Therefore, when a travel guide map based on a new location is generated, the number of access to the physical storage medium such as a CD-ROM or hard disk can be reduced, thereby improving memory loading speed for displaying the map.
Next, the preferred embodiments of the present invention will be sequentially described with reference to
In the first embodiment of the present invention, when a travel guide map based on a new location is generated again as the position of a vehicle, only a certain number of map segments are retrieved from the physical storage medium such as a CD-ROM or hard disk to generated the travel guide map, thereby making map displaying speed faster.
To this end, in the first embodiment of the present invention, map segments required from displaying a travel guide map based on a current vehicle location on the display unit are first selected among a predetermined number of map segments that have been loaded on the operation memory to display a travel guide map based on a previous location on the display unit.
That is, as shown in
Further, map segments identical with the detected central map segment and adjacent map segments among a predetermined number of map segments that have been loaded on the operation memory to display a travel guide map based on a previous location are selected as map segments usable for displaying a travel guide map based on the current vehicle location on the display unit (S603).
At this time, the adjacent map segments are sequentially detected according to the degree of proximity to the central map segment, and the entire map is preferably a map divided into map segments with a predetermined size based on latitude and longitude.
Meanwhile, the map segments selected as those usable for displaying the travel guide map based on the current vehicle location on the display unit as described above are designated as properties (S604), and remaining map segments are designated as victims.
At this time, it is preferred that predetermined different marks be assigned to the map segments to identify those designated as the properties and victims. For example, it is preferred that a binary bit flag of “1” be assigned to the properties, while a binary bit flag of “0” be assigned to the victims. The marks are initialized whenever the position of the vehicle varies.
In the first embodiment of the present invention, as for the map segments designated as the properties, they are reinserted into the operation memory (S610) even though they have been deleted from the operation memory in a predetermined order, e.g., in the FIFO manner (S606, S607). For example, the map segments designated as the properties are deleted at their turns in the FIFO manner. The deleted map segments are added to an insertion queue, and the map segments added to the insertion queue are reinserted into the operation memory in a relevant order.
On the other hand, the map segments designated as the victims are completely deleted from the operation memory, and remaining map segments required for displaying the travel guide map based on the current vehicle location are retrieved from the physical storage medium with the entire map stored therein (S608, S609) and are then updated into the operation memory (S611). At this time, the map segments designated as the victims are deleted from the operation memory in the practicable FIFO manner, and the map segments retrieved from the physical storage medium are inserted into the operation memory.
The map segments updated into the operation memory in such a manner, and the map segments designated in advance as the properties are loaded on a screen memory.
As a result, according to the first embodiment of the present invention, when a travel guide map is generated again based on a new location as the position of the vehicle varies, only a certain number of map segments are retrieved from the physical storage medium such as a CD-ROM or hard disk to generate the travel guide map, thereby making map-displaying speed faster.
Next, the second embodiment of the present invention will be described with reference to
As shown in
Then, map segment numbers required for displaying a travel guide map based on a new location on the display unit are received from the control unit (S701), and the map segment numbers loaded on the operation memory are compared with the map segment numbers received in step S701 (S702).
Using the comparison results, map segments usable for displaying the travel guide map based on the new location on the display unit are selected among the map segments loaded on the operation memory (S702).
Thereafter, the selected map segments are designated as properties, and remaining map segments are designated as victims.
In the second embodiment of the present invention, it is then determined whether the operation memory is full (S704). If it is determined that the operation memory is not full, remaining map segments required for displaying a travel guide map based on a current vehicle location are retrieved from the physical storage medium with the entire map stored therein and are then updated into the operation memory (S706).
On the contrary, if it is determined that the operation memory is full, the map segments which have been previously loaded on the operation memory are sequentially deleted one by one in order to fill the interior of the operation memory with map segments usable for displaying the travel guide map based on the current vehicle location (S705).
Then, it is determined whether the deleted map segments are those designated as properties or victims (S707).
If it is determined that the deleted map segments are those designated as properties, they are reinserted into the operation memory (S708). If it is determined that the deleted map segments are those designated as victims, they are completely deleted from the operation memory. Thereafter, remaining map segments required for displaying the travel guide map based on the current vehicle location on the display unit are sequentially retrieved from the physical storage medium with the entire map stored therein and then are updated into the operation memory.
Here, it is preferred that predetermined different marks be assigned to the respective map segments designated as properties and victims so as to identify them, and the marks be initialized whenever the position of the vehicle varies.
According to the second embodiment of the present invention, when the travel guide map is generated again based on the new location as the position of the vehicle varies, map data loading speed can be faster by preventing reusable map segments among the map segments loaded on the operation memory from being unnecessarily deleted, retrieved again from the physical storage medium and inserted into the operation memory.
Finally, the third embodiment of the present invention will be described with reference to
In the third embodiment of the present invention, the speed of loading map data on the screen memory, which has been required for displaying a travel guide map on the display unit, becomes faster by loading the map data of the travel guide map on the screen memory while minimizing the number of access to the physical storage medium such as a CD-ROM.
To this end, in the third embodiment of the present invention, a certain number of map segments required for generating a travel guide map based on a new location are updated into the operation memory as the position of the vehicle varies.
More specifically, GPS data are first received (S800), and coordinates of a current vehicle location is calculated using the GPS data (S801). Then, a map segment including the coordinates of the current vehicle location, and a predetermined number of adjacent map segments surrounding the map segment are detected (S802, S803, S804).
Subsequently, the operation memory is searched (S805), map segments identical with the detected map segments are selected among map segments stored in the operation memory (S806), and remaining map segments except the selected map segments are deleted from the operation memory (S807).
Thereafter, the physical storage medium with the entire map stored therein is searched (S808) to retrieve remaining map segments required for generating the travel guide map based on the new position, and the retrieved map segments are then updated into empty are as of the operation memory which are obtained by deleting the map segments (S809).
Finally, access is made to the operation memory instead of the physical storage medium with the entire map stored therein in response to a display request input from the outside, and the map segments updated into the operation memory are loaded on the screen memory (not shown) as described above (S811), thereby displaying the travel guide map generated in step S812 on the display unit using the map segments loaded on the screen memory (S813).
According to the third embodiment of the present invention, the map data loading speed becomes faster in such a manner that the certain number of map segments required for generating the travel guide map based on the new location as the position of the vehicle varies are detected and then updated into the operation memory, and the updated map segments are retrieved from the operation memory and then loaded on the screen memory.
With the method for managing map data for a vehicle according to the present invention described above, upon display of the map data on a display unit, the number of access to a physical storage medium with an entire map stored therein is decreased to reduce access overhead, thereby improving the displaying speed of the map data. Further, there is an advantage in that map segments reusable as the vehicle travels are prevented from being designated as victims, thereby making the loading of the map data on a memory faster.
Although the present invention has been illustrated and described in connection with the preferred embodiment, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention defined by the appended claims, and such modifications and changes will fall within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2003-0072854 | Oct 2003 | KR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4550317 | Moriyama et al. | Oct 1985 | A |
| 4742558 | Ishibashi et al. | May 1988 | A |
| 5444618 | Seki et al. | Aug 1995 | A |
| 5523765 | Ichikawa | Jun 1996 | A |
| 5893898 | Tanimoto | Apr 1999 | A |
| 6125367 | Na | Sep 2000 | A |
| 6334088 | Taniguchi et al. | Dec 2001 | B1 |
| 6604046 | Watermulen et al. | Aug 2003 | B1 |
| 20040034469 | Kim | Feb 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| 0 510 939 | Apr 1992 | EP |
| 0 945 706 | Sep 1999 | EP |
| Number | Date | Country | |
|---|---|---|---|
| 20050085996 A1 | Apr 2005 | US |
