Navigation Technologies Corporation

Joseph Ciprian

David S Lampert

Robert P Fernekes

Bishnu P Phuyal

A vehicle positioning application in a navigation system provides for determining a change of vehicle heading using differential wheel speed sensors and compensates for dynamic and static changes in the wheel radii.

Vehicle heading change determination using compensated differential wheel speed

A program and method are disclosed that provide for determining a position of a vehicle relative to a road network represented by a geographic database. An intermediate position density is determined along a plurality of road segments in the road network by shifting a prior position density which had been determined along the plurality of road segments by a distance traveled by the vehicle since the prior position density had been determined. Then, the intermediate position density is modified to take into account sensor-derived data received since the prior position density had been determined to form a new position density. The sensor-derived data include data indicating three metrics, namely (1) a position of the vehicle, (2) a heading of the vehicle, and (3) a curvature history. The curvature history represents a change of heading of the vehicle as a function of distance. Then, the position of the vehicle is determined to be that location along the plurality of road segments at which the new position density is greatest. Also disclosed is a program and method that operate when it has been determined that the vehicle has just completed a turn. According to this program and method, processed data values from the sensors that indicate the vehicle position are adjusted to correspond to a position along the road network as represented by the geographic database. Further, if it has been determined that the vehicle is located on a straight road segment after having completed a turn, processed data values of the sensors that indicate a vehicle heading are adjusted to correspond to the heading of the straight road segment upon which the vehicle has been determined to be located.

Growing community of inventors

Bloomingdale, IL, United States of America

Joseph Ciprian