Patent ID: 7561964
Filing Date: 2009-07-14
Classification: G01C

Abstract:
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: 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.