Navigation system for a vehicle with route recalculation between multiple locations

• US 5,608,635 A
• Filed: 11/17/1994
• Issued: 03/04/1997
• Est. Priority Date: 04/14/1992
• Status: Expired due to Term

• Current Assignee: TomTom International BV (TomTom NV)
• Original Assignee: Zexel Corporation
• Inventors: Tamai, Haruhisa
• Primary Examiner(s): Chin, Gary
• Application Number:
  US08/341,518
• Time in Patent Office: 838 Days
• Field of Search: 364/443, 364/444, 364/449, 73/178 R, 340/988, 340/990, 340/995
• US Class Current: 701/209
• CPC Class Codes: G01C 21/3461 Preferred or disfavoured areas, e.g. dangerous zones, toll or emission zones, intersections, manoeuvre types, segments such as motorways, toll roads, ferries
• CPC Class Codes: G01C 21/3605 Destination input or retrieval
• CPC Class Codes: G08G 1/096827 where the route is computed onboard
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data
• CPC Class Codes: G08G 1/096861 where the immediate route instructions are output to the driver, e.g. arrow signs for next turn

Abstract

A vehicle navigation system guides a driver along an optimal route from a starting point to a destination, either of which can be specified in categorical terms. That is, the starting point need not be on a road, and the categorical destination can be entered as "nearest gas station" or "closest hardware store." The system selects a number of possible destinations that conform to the driver'"'"'s specifications and computes, simultaneously for each particular area on a digitally-stored map, possible optimal routes from the vehicle'"'"'s current position to each possible destination. The optimal route is selected according to conditions of shortest distance, fastest time, or fewest turns set individually or in any combination by the driver, who is guided along the optimal route by messages on a display. A similar procedure, in which a plurality of possible starting points is proposed, yields the optimal route to a destination from an indefinitely specified starting point. A weighting equation gives a priority within a particular map area to each possible optimal route. Thus the navigation system of the present invention finds most efficiently a desired destination on an optimal route from the vehicle'"'"'s current position or from a starting point from which the vehicle'"'"'s current position may be reached.

Claims

1. A vehicle navigation system that displays continuously a direction of a vehicle'"'"'s motion, comprising:

means for determining a current position of said vehicle;

means for storing and retrieving a plurality of map data;

means for partitioning said map data into a plurality of map areas;

means for entering information about at least one proposed categorical destination;

said information including at least one element that does not recite specific geographic coordinates;

means for selecting from one of a plurality of possible destinations in said storing means as said at least one proposed categorical destination in accordance with said information;

means, responsive to said means for selecting, for computing a plurality of proposed routes to said at least one proposed categorical destination;

means for comparing said plurality of proposed routes to geographic destinations that correspond to said at least one proposed categorical destination in each partitioned map area;

said means for computing being effective to choose a single geographic destination and a single optimal route thereto, whereby said single geographic destination and said single optimal route satisfy a preselected criterion of optimality derived from at least one variable independent of location and distance; and

means, responsive to said means for computing, for displaying a plurality of navigational data to guide said vehicle along said optimal route from said vehicle'"'"'s current position to said single geographic destination.

2. A vehicle navigation system as in claim 1, wherein:

said means for determining includes a shaft sensor, a terrestrial magnetism sensor, and a microcomputer;

said means for determining further includes means for applying signals from said shaft sensor and said terrestrial magnetism sensor to said microcomputer; and

said microcomputer includes means tier computing said current position from said signals.

3. A vehicle navigation system as in claim 1, wherein said means for storing and retrieving includes a CD ROM.

4. A vehicle navigation system as in claim 1, wherein said means for storing and retrieving includes an IC card.

5. A vehicle navigation system as in claim 1, wherein said means for storing and retrieving includes a remote computer database.

6. A vehicle navigation system as in claim 1, wherein said means for entering includes a keypad.

7. A vehicle navigation system as in claim 1, wherein said means for entering includes a voice data entry unit.

8. A vehicle navigation system as in claim 1, wherein said means for selecting includes a microcomputer.

9. A vehicle navigation system as in claim 1, wherein said means for computing includes a microcomputer.

10. A vehicle navigation system as in claim 1, wherein said means for displaying includes a CRT.

11. A vehicle navigation system as in claim 1, wherein said means for displaying includes a LCD.

12. A vehicle navigation system as in claim 1, wherein said preselected criterion of optimality is derived by combining a minimum time, a minimum distance, and a minimum number of turns.

13. A vehicle navigation system that displays continuously a direction of a vehicle'"'"'s motion, which comprises:

means for determining a current position of said vehicle;

means for storing and retrieving a plurality of map data;

means for partitioning said map data into a plurality of map areas;

means for entering information about at least one categorical destination;

means for selecting from one of a plurality of possible destinations in said storing means as said at least one proposed categorical destination in accordance with said information;

means, responsive to said means for entering, for selecting from said plurality of map data proposed starting points of a route for said vehicle to travel;

means, responsive to said means for selecting, for computing a plurality of proposed routes from said proposed starting points to said at least one categorical destination;

means for comparing said plurality of proposed routes from each of said proposed starting points with each other in each partitioned map area;

said means for computing being effective to choose a single one of said starting points and a single optimal one of said plurality of proposed routes therefrom such that said single starting point and said single optimal route satisfy a preselected criterion of optimality derived from at least one variable other than distance; and

means, responsive to said means for computing, for displaying a plurality of navigational data to guide said vehicle along said single optimal route from said vehicle'"'"'s current position to said at least one categorical destination.

14. A vehicle navigation system as in claim 13, wherein:

said means for determining includes a shaft sensor, a terrestrial magnetism sensor, and a microcomputer;

said means for determining further includes means for applying signals from said shaft sensor and said terrestrial magnetism sensor to said microcomputer; and

said microcomputer includes means for computing said current position from said signals.

15. A vehicle navigation system as in claim 13, wherein said means for storing and retrieving includes a CD ROM.

16. A vehicle navigation system as in claim 13, wherein said means for storing and retrieving includes an IC card.

17. A vehicle navigation system as in claim 13, wherein means for storing and retrieving includes a remote computer database.

18. A vehicle navigation system as in claim 13, wherein said means for entering includes a keypad.

19. A vehicle navigation system as in claim 13, wherein said means for entering includes a voice data entry unit.

20. A vehicle navigation system as in claim 13, wherein said means for selecting includes a microcomputer.

21. A vehicle navigation system as in claim 13, wherein said means for computing includes a microcomputer.

22. A vehicle navigation system as in claim 13, wherein said means for displaying includes a CRT.

23. A vehicle navigation system as in claim 13, wherein said means for displaying includes a LCD.

24. A vehicle navigation system as in claim 13, wherein said preselected criterion of optimality is derived by combining a minimum time, a minimum distance, and a minimum number of turns.

25. A vehicle navigation system that displays continuously a direction of a vehicle'"'"'s motion, which comprises:

a CD ROM for storing and retrieving a plurality of map data;

said map data disposed to be partitioned into a plurality of map areas;

a shaft sensor;

a terrestrial magnetism sensor;

said shaft sensor and said terrestrial magnetism sensor including means for sending signals for determining a present location of said vehicle;

a keypad for entering information about at least one proposed categorical destination;

said information including at least one element that does not recite specific geographic coordinates;

a microcomputer effective for selecting from one of a plurality of possible destinations in said CD ROM as said at least one proposed categorical destination in accordance with said information;

said microcomputer being further effective for computing a plurality of proposed routes to said at least one proposed categorical destination;

said microcomputer being further effective for comparing said plurality of proposed routes to geographic destinations that correspond to said at least one proposed categorical destination in each partitioned map area;

said microcomputer being further effective to choose a single geographic destination and a single optimal route thereto, whereby said single geographic destination and said single optimal route satisfy a preselected criterion of optimality;

said microcomputer being further effective for selecting from said plurality of map data at least one proposed starting point of said single optimal route;

said microcomputer being further effective for computing a plurality of proposed routes from said at least one proposed starting point to said at least one proposed categorical destination for all geographic locations that correspond to said at least one proposed starting point in each partitioned map area;

said preselected criterion of optimality being derived from at least one variable other than geographical location and distance;

a CRT display for displaying information in response to signals from said microcomputer; and

said CRT display being effective for displaying a plurality of navigational data to guide said vehicle along said single optimal route from said vehicle'"'"'s current position to said at least one proposed categorical destination.

26. A vehicle navigation system as in claim 25, wherein said first and said second preselected criteria of optimality are derived by combining a minimum time, a minimum distance, and a minimum number of turns.

27. A vehicle navigation system that displays continuously a direction of a vehicle'"'"'s motion, comprising:

means for determining a current position of said vehicle;

means for storing and retrieving map data;

means for entering criteria for selection of a categorical destination and a route thereto;

said criteria including at least one criterion that does not recite specific geographic coordinates;

means for identifying possible destinations in said storing means as said categorical destination according to said criteria;

means for computing possible routes from said current position to said possible destinations;

said means for computing being effective to choose, according to said criteria, an optimal one of said possible destinations and, from said possible routes, an optimal route thereto; and

means, responsive to said means for computing, for displaying a plurality of navigational data to guide said vehicle along said optimal route.