Apparatus for road path searching applicable to car navigation system and operation method thereof
First Claim
1. In a navigation system for processing stored electrical data representative of pre-defined locations within a given geographic area, apparatus for searching through said data to find a path between first and second geographic points situated within said area and for displaying the path comprising:
- storage means (2) for storing electrical data which repeatedly defines a map of the area but at first and second different display levels, the data for the first and second display levels defining node locations that collectively represent roads situated in the area that are to be depicted at said each display level such that the first and second display levels collectively represent said map at first and second pre-defined levels of detail with the first level having more detail than said second level, the data being organized into respective first and second data groups for, respectively, the first and second display levels such that the data group for the first level includes the data group for the second level,processing means (1, 3, 5, 6, 7,
8), operative in conjunction with the storage means, for determining the path between said first and second points comprising;
designating means (11), responsive to said first and second geographic points, for designating first and second positions on the first level of the map and corresponding to the first and second geographic points,adjacent node detecting means (13), responsive to the first and second positions, for detecting a plurality of each of first and second node locations in the first level and respectively adjacent to said first and second positions so as to yield corresponding first and second pluralities of adjacent node positions,existence detecting means (14,
18), operative in response to said adjacent node detecting means, for detecting whether said second level contains at least one of each of the pluralities of said first and second adjacent node positions and for providing a result indicative thereof,determining means (20, 21,
22), responsive to said adjacent node detecting means and to the result provided by said existence detecting means, for selecting one of each of the pluralities of said first and second adjacent node positions as the first and second positions such that if the pluralities of the first and second adjacent node positions contain node locations existing in said second level then the first and second positions are taken, in a pre-defined manner, to be respective ones of said node locations existing in the second level in preference to node locations existing at the first level in the pluralities of said first and second adjacent node positions; and
changing means (19), operative in response to the result provided by said existence detecting means, for subsequently changing the level of the map used by said adjacent node detecting means from the first to the second level in the event said first and second positions exist in said second level,decision means (17), responsive to said first and second positions, for invoking said adjacent node detecting means to detect next successive pluralities of said first and second node locations until the first and second positions satisfy a pre-determined criteria, anddisplay means (4), responsive to said processing means, for displaying paths between successive ones of said first positions and between successive ones of said second positions so as to depict the path between said first and second geographic points.
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Accused Products
Abstract
A road path searching apparatus applicable to a car navigation system is disclosed. Road map data with different level of detail for defining a predetermined area is stored previously in a memory device. First, nodes Nai and Nbj adjacent to each of the search nodes Pa and PB are detected based on map data having a high level of detail. When nodes Nai and Nbj exist on a map of a lower level of detail, a map of one lower level of detail is selected as a map to be used in the searching process. Accordingly, as following searching process is performed based on the map data of lower level of detail, required processing time is reduced.
45 Citations
12 Claims
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1. In a navigation system for processing stored electrical data representative of pre-defined locations within a given geographic area, apparatus for searching through said data to find a path between first and second geographic points situated within said area and for displaying the path comprising:
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storage means (2) for storing electrical data which repeatedly defines a map of the area but at first and second different display levels, the data for the first and second display levels defining node locations that collectively represent roads situated in the area that are to be depicted at said each display level such that the first and second display levels collectively represent said map at first and second pre-defined levels of detail with the first level having more detail than said second level, the data being organized into respective first and second data groups for, respectively, the first and second display levels such that the data group for the first level includes the data group for the second level, processing means (1, 3, 5, 6, 7,
8), operative in conjunction with the storage means, for determining the path between said first and second points comprising;designating means (11), responsive to said first and second geographic points, for designating first and second positions on the first level of the map and corresponding to the first and second geographic points, adjacent node detecting means (13), responsive to the first and second positions, for detecting a plurality of each of first and second node locations in the first level and respectively adjacent to said first and second positions so as to yield corresponding first and second pluralities of adjacent node positions, existence detecting means (14,
18), operative in response to said adjacent node detecting means, for detecting whether said second level contains at least one of each of the pluralities of said first and second adjacent node positions and for providing a result indicative thereof,determining means (20, 21,
22), responsive to said adjacent node detecting means and to the result provided by said existence detecting means, for selecting one of each of the pluralities of said first and second adjacent node positions as the first and second positions such that if the pluralities of the first and second adjacent node positions contain node locations existing in said second level then the first and second positions are taken, in a pre-defined manner, to be respective ones of said node locations existing in the second level in preference to node locations existing at the first level in the pluralities of said first and second adjacent node positions; andchanging means (19), operative in response to the result provided by said existence detecting means, for subsequently changing the level of the map used by said adjacent node detecting means from the first to the second level in the event said first and second positions exist in said second level, decision means (17), responsive to said first and second positions, for invoking said adjacent node detecting means to detect next successive pluralities of said first and second node locations until the first and second positions satisfy a pre-determined criteria, and display means (4), responsive to said processing means, for displaying paths between successive ones of said first positions and between successive ones of said second positions so as to depict the path between said first and second geographic points. - View Dependent Claims (2, 3, 4)
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5. In a navigation system for processing stored electrical data representative of pre-defined locations within a given geographic area, apparatus for searching through said data to find a path between first and second geographic points situated within said area and for displaying the path comprising:
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storage means (2) for storing electrical data which repeatedly defines a map of the area but at first and second different display levels, the data for the first and second display levels defining node locations that collectively represent roads situated in the area that are to be depicted at said each display level such that the first and second display levels collectively represent said map at first and second pre-defined levels of detail with the first level having more detail than said second level, the data being organized into respective first and second data groups for, respectively, the first and second display levels such that the data group for the first level includes the data group for the second level, processing means (1, 3, 5, 6, 7,
8), operative in conjunction with the storage means, for determining the path between said first and second points comprising;designating means (31), responsive to said first and second geographic points, for designating first and second positions on the first level of the map and corresponding to the first and second geographic points, distance determining means (32) for determining a geographic distance between geographic points represented by said first and second positions on the first level of the map, selecting means (34, 36, 37,
38), responsive to a value of the distance, for selecting said first or second data groups corresponding to said first or second display levels as a selected data group in which to search for said path, andsearching means (40, 41, 42,
43) for searching through said selected data group so as to locate successive ones of said node locations therein as successive ones of first and second positions in order to define a path therebetween, anddisplay means (4), responsive to said processing means, for displaying paths between successive ones of said first positions and between successive ones of said second positions so as to depict the path between said first and second geographic points. - View Dependent Claims (6, 7, 8)
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9. In a navigation system for processing stored electrical data representative of pre-defined locations within a given geographic area, said system comprising storage means (2) for storing electrical data which repeatedly defines a map of the area but at first and second different display levels, the data for the first and second display levels defining node locations that collectively represent roads situated in the area that are to be depicted at said each display level such that the first and second display levels collectively represent said map at first and second pre-defined levels of detail with the first level having more detail than said second level, the data being organized into respective first and second data groups for, respectively, the first and second display levels such that the data group for the first level includes the data group for the second level, said system further comprising processing means (1, 3, 5, 6, 7, 8) operative in conjunction with said storage means for determining a path between first and second geographic points situated in said area, and display means (4) responsive to said processing means for displaying said path, a method for searching through said data to find the path between the first and second geographic points and for displaying the path comprising the steps of:
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in said processing means; designating, in response to said first and second geographic points, first and second positions on the first level of the map and corresponding to the first and second geographic points, first detecting, in response to the first and second positions, a plurality of each of first and second node locations in the first level and respectively adjacent to said first and second positions so as to yield corresponding first and second pluralities of adjacent node positions, second detecting, in response to said first detecting step, whether said second level contains at least one of each of the pluralities of said first and second adjacent node positions and providing a result indicative thereof, selecting, in responsive to said first detecting step and to the result provided by said second detecting step, one of each of the pluralities of said first and second adjacent node positions as the first and second positions such that if the pluralities of the first and second adjacent node positions contain node locations existing in said second level then the first and second positions are taken, in a pre-defined manner, to be respective ones of said node locations existing in the second level in preference to node locations existing at the first level in the pluralities of said first and second adjacent node positions, subsequently changing, in response to the result provided by said second detecting step, the level of the map used by said first detecting step from the first to the second level in the event said first and second positions exist in said second level, and invoking, in response to said first and second positions, said first detecting step to detect next successive pluralities of said first and second node locations until the first and second positions satisfy a pre-determined criteria, and in the display means; displaying paths between successive ones of said first positions and between successive ones of said second positions so as to depict the path between said first and second geographic points. - View Dependent Claims (10)
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11. In a navigation system for processing stored electrical data representative of pre-defined locations within a given geographic area, said system comprising storage means (2) for storing electrical data which repeatedly defines a map of the area but at first and second different display levels, the data for the first and second display levels defining node locations that collectively represent roads situated in the area that are to be depicted at said each display level such that the first and second display levels collectively represent said map at first and second pre-defined levels of detail with the first level having more detail than said second level, the data being organized into respective first and second data groups for, respectively, the first and second display levels such that the data group for the first level includes the data group for the second level, said system further comprising processing means (1, 3, 5, 6, 7, 8) operative in conjunction with said storage means for determining a path between first and second geographic points situated in said area, and display means (4) responsive to said processing means for displaying said path, a method for searching through said data to find the path between the first and second geographic points and for displaying the path comprising the steps of:
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in said processing means; designating, in response to said first and second geographic points, first and second positions on the first level of the map and corresponding to the first and second geographic points, determining a geographic distance between geographic points represented by said first and second positions on the first level of the map, selecting, in response to a value of the distance, said first or second data groups corresponding to said first or second display levels as a selected data group in which to search for said path, and searching through said selected data group so as to locate successive ones of said node locations therein as successive ones of first and second positions in order to define a path therebetween, and in the display means; displaying paths between successive ones of said first positions and between successive ones of said second positions so as to depict the path between said first and second geographic points. - View Dependent Claims (12)
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Specification