Method for managing map data for vehicle

• US 20050085996A1
• Filed: 10/12/2004
• Published: 04/21/2005
• Est. Priority Date: 10/20/2003
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Young In, Jde, Moon Jeung, Park, Chang Won
• Granted Patent: US 7,440,849 B2
• Time in Patent Office: Days
• US Class Current: 701/208
• CPC Class Codes: G01C 21/3844 Data obtained from position sensors only, e.g. from inertial navigation

Abstract

The present invention relates to a method for managing map data for a vehicle using a navigation system, 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. To this end, 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 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.

Claims

1. A method for managing map data for a vehicle, comprising the steps of:

(a) selecting map segments usable for displaying a travel guide map based on a current vehicle location on a display unit, among a predetermined number of map segments which have been loaded on an operation memory to display a travel guide map based on a previous vehicle location on the display unit;

(b) designating the map segments selected in step (a) as properties, and remaining map segments as victims; and

(c) deleting the map segments designated as the victims in step (b), retrieving remaining map segments required for displaying the travel guide map based on the current vehicle location on the display unit from a physical storage medium with an entire map stored the rein, and updating the operation memory with the retrieved map segments.

2. The method as claimed in claim 1, after step (c), further comprising the step of:

(d) loading the map segments updated into the operation memory and the map segments designated as the properties in step (b) on a screen memory.

3. The method as claimed in claim 1, wherein step (a) comprises the steps of:

(a-1) calculating coordinates of the current vehicle location using GPS data received by a GPS receiver;

(a-2) detecting a central map segment including the coordinates of the current vehicle location calculated in step (a-1), and a predetermined number of adjacent map segments surrounding the central map segment to display a map with a predetermined size on the display unit; and

(a-3) selecting map segments, which are identical with the central map segment and adjacent map segments detected in step (a-2) among the predetermined number of map segments loaded on the operation memory to display the travel guide map based on the previous vehicle location on the display unit, as map segments usable for displaying the travel guide map based on the current vehicle location on the display unit.

4. The method as claimed in claim 3, wherein the adjacent map segments are detected based on the degree of proximity to the central map segment.

5. The method as claimed in claim 1, wherein the entire map is a map divided into map segments with a predetermined size based on latitude and longitude.

6. The method as claimed in claim 1, wherein step (c) comprises the step of:

deleting the map segments designated as the victims from the operation memory in a first-in first-out (FIFO) manner, and inserting the map segments retrieved from the physical storage medium into the operation memory.

7. The method as claimed in claim 1, between steps (b) and (c), further comprising the step of:

assigning predetermined marks to the map segments designated as the properties and the victims to identify the map segments, respectively.

8. The method as claimed in claim 7, wherein the marks are initialized whenever the position of the vehicle varies.

9. The method as claimed in claim 7, wherein the marks are assigned to the map segments such that a binary bit flag of “

1”

is assigned to the properties while a binary bit flag of “

0”

is assigned to the victims.

10. The method as claimed in claim 7, separately from step (c) after the step of assigning the marks, further comprising the step of:

managing the map segments designated as the properties in step (b) so that they can be reinserted even though they have been deleted from the operation memory in a first-in first-out (FIFO) manner.

11. The method as claimed in claim 10, the managing step comprises the steps of:

deleting the map segments designated as the properties at their turns in the FIFO manner;

adding the map segments deleted in the deleting step to an insertion queue; and

reinserting the map segments added to the insertion queue in the adding step into the operation memory in a relevant order.

21. The method as claimed in any one of claims 1 to 20, wherein the operation memory comprises a cache memory.

12. A method for managing map data for a vehicle, comprising the steps of:

(a) selecting map segments usable for displaying a travel guide map based on a current vehicle location on a display unit, among a predetermined number of map segments which have been loaded on an operation memory to display a travel guide map based on a previous vehicle location on the display unit;

(b) designating the map segments selected in step (a) as properties, and remaining map segments as victims;

(c) deleting the map segments loaded on the operation memory in sequence one by one so as to cause the operation memory to be filled with the map segments usable for displaying the travel guide map based on the current vehicle location on the display unit;

(d) determining whether the map segments deleted in step (c) are map segments designated as the properties or victims;

(e) if it is determined in step (d) that the deleted map segments are those designated as the properties, reinserting the map segments into the operation memory.

13. The method as claimed in claim 12, after step (d), further comprising the step of:

(f) if it is determined in step (d) that the deleted map segments are those designated as the victims, completely deleting the map segments from the operation memory, sequentially retrieving remaining map segments required for displaying the travel guide map based on the current vehicle location on the display unit from a physical storage medium with an entire map stored therein, and updating the operation memory with the retrieved map segments.

14. The method as claimed in claim 12, wherein the designation of the map segments as the properties and the victims in step (b) is performed using predetermined different marks.

15. The method as claimed in claim 14, wherein the marks are initialized whenever the position of the vehicle varies.

16. The method as claimed in claim 12, between steps (b) and (c), further comprising the step of:

determining whether the operation memory is full.

17. The method as claimed in claim 16, further comprising the step of:

if it is determined that the operation memory is not full, sequentially retrieving remaining map segments required for displaying the travel guide map based on the current vehicle location on the display unit from a physical storage medium with an entire map stored therein, and updating the operation memory with the retrieved map segments.

18. A method for managing map data for a vehicle, comprising the steps of:

(a) detecting a predetermined number of map segments required for displaying a travel guide map based on a new location on a display unit as the position of the vehicle varies, and updating an operation memory with the detected map segments; and

(b) accessing the operation memory instead of a physical storage medium with an entire map stored therein in response to a display request input from the outside, and loading the map segments updated in step (a) on a screen memory.

19. The method as claimed in claim 18, wherein step (a) comprises the steps of:

(a-1) detecting the predetermined number of map segments required for displaying the travel guide map based on the new location on the display unit as the position of the vehicle varies;

(a-2) searching the operation memory, and selecting map segments identical with the map segments detected in step (a-1) among a predetermined number of map segments which have been loaded on the operation memory to display a travel guide map based on a previous vehicle location on the display unit;

(a-3) deleting remaining map segments except the map segments selected in step (a-2); and

(a-4) retrieving remaining map segments required for displaying the travel guide map based on the new location on the display unit from the physical storage medium with the entire map stored therein, and updating empty areas of the operation memory obtained through the deletion in step (a-3) with the retrieved map segments.

20. The method as claimed in claim 19, wherein step (a-1) comprises the steps of:

(a-1-1) calculating coordinates of the current vehicle location using GPS data received by a GPS receiver; and

(a-1-2) detecting a central map segment including the coordinates of the current vehicle location calculated in step (a-1-1), and a predetermined number of adjacent map segments surrounding the central map segment to display a map with a predetermined size on the display unit.