Off-route recalculation method and apparatus for navigation system

• US 7,561,964 B2
• Filed: 01/05/2006
• Issued: 07/14/2009
• Est. Priority Date: 01/05/2006
• Status: Active Grant

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Vu, Tien
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Amin; Bhavesh V
• Application Number:
  US11/326,184
• Publication Number:
  US 20070156334A1
• Time in Patent Office: 1,286 Days
• Field of Search: 701200-224, 340988-996
• US Class Current: 701/210
• CPC Class Codes: G01C 21/3415 Dynamic re-routing, e.g. recalculating the route when the user deviates from calculated route or after detecting real-time traffic data or accidents

Abstract

An off-route recalculation method and apparatus for a navigation system calculates a new route when a vehicle is deviated from an originally calculated route to a destination. The method is comprised of the steps of: detecting whether a user vehicle has deviated from an originally calculated route; predicting a path that a user is likely to take until a new route to the destination is calculated; calculating a predicted distance that the user vehicle advances through the predicted path during a time the new route to the destination is calculated and during a turn prepare time, thereby determining a start position of the new route; calculating the new route to the destination incorporating the start position.

Claims

1. A method of calculating a route to a destination, comprising the following steps of:

detecting whether a user has deviated from an originally calculated route to a destination;

predicting a path that a user is likely to take after the user has deviated from the original route until a new route to the destination is calculated by examining data regarding road segments retrieved from a map data storage;

calculating a predicted distance that the user advances through the predicted path during a time the new route to the destination is calculated and a turn prepare time, thereby determining a start position of a new route to the destination; and

calculating a new route to the destination incorporating the start position so that the new route allows the user a sufficient time for next turn maneuver while enabling to quickly reach the destination;

wherein the predicted distance is calculated by the following formula;

D=(ECT+TPT)*AVS

where D denotes the predicted distance, ECT denotes an estimated calculation time which is a time required for producing a new calculated route to the destination, TPT denotes a turn prepare time which is a time length appropriate for the user to prepare for turning at a next intersection, and AVS denotes an average vehicle speed.

2. A method of recalculating a route to a destination as defined in claim 1, further comprising a step of starting route guidance for the new route as soon as the calculation for the new route is completed so as to give the user a time equal to or greater than the turn prepare time before the next turn maneuver.

3. A method of recalculating a route to a destination as defined in claim 1, wherein the step of predicting the path includes a step of comparing angles formed by the road segments.

4. A method of recalculating a route to a destination as defined in claim 1, wherein the step of predicting the path includes a step of comparing road names assigned to the road segments.

5. A method of recalculating a route to a destination as defined in claim 1, wherein the step of predicting the path includes a step of comparing function classes of the road segments.

6. A method of recalculating a route to a destination as defined in claim 1 wherein the estimated calculation time is a predefined value set by a manufacturer or a value that is obtained by an experimental calculation operation.

7. A method of recalculating a route to a destination as defined in claim 1, wherein the estimated calculation time is renewed by a value obtained by an experimental calculation operation or a value obtained by an actual route calculation operation.

8. A method of recalculating a route to a destination as defined in claim 1, wherein a value for the turn prepare time is adjustable by the user.

9. An apparatus for calculating a route to a destination, comprising:

detection means for detecting whether a user has deviated from an originally calculated route to a destination;

prediction means for predicting a path that a user is likely to take after the user has deviated from the original route until a new route to the destination is calculated by examining data regarding road segments retrieved from a map data storage;

calculation means for calculating a predicted distance that the user advances through the predicted path during a time the new route to the destination is calculated and a turn prepare time, thereby determining a start position of a new route to the destination; and

calculation means for calculating a new route to the destination incorporating the start position so that the new route allows the user a sufficient time for next turn maneuver while enabling to quickly reach the destinations;

wherein the predicted distance is calculated by the following formula;

D=(ECT+TPT)*AVS

where D denotes the predicted distance, ECT denotes an estimated calculation time which is a time required for producing a new calculated route to the destination, TPT denotes a turn prepare time which is a time length appropriate for the user to prepare for turning at a next intersection, and AVS denotes an average vehicle speed.

10. An apparatus for recalculating a route to a destination as defined in claim 9, further comprising start means for starting route guidance for the new route as soon as the calculation for the new route is completed so as to give the user a time equal to or greater than the turn prepare time before the next turn maneuver.

11. An apparatus for recalculating a route to a destination as defined in claim 9, wherein said prediction means for predicting the path includes comparison means for comparing angles formed by the road segments.

12. An apparatus for recalculating a route to a destination as defined in claim 9, wherein said prediction means for predicting the path includes comparison means for comparing road names assigned to the road segments.

13. An apparatus for recalculating a route to a destination as defined in claim 9, wherein said prediction means for predicting the path includes comparison means for comparing function classes of the road segments.

14. An apparatus for recalculating a route to a destination as defined in claim 9, wherein the estimated calculation time is a predefined value set by a manufacturer or a value that is obtained by an experimental calculation operation.

15. An apparatus for recalculating a route to a destination as defined in claim 9, wherein the estimated calculation time is renewed by a value obtained by an experimental calculation operation or a value obtained by an actual route calculation operation.

16. An apparatus for recalculating a route to a destination as defined in claim 9, wherein a value for the turn prepare time is adjustable by the user.