Patent ID: 6401036
Filing Date: 2002-06-04
Classification: G01C,G01S

Abstract:
A vehicle navigational system having built-in error correction comprising:(a) a distance traveled sensor; (b) a heading sensor having a bias that drifts over time; (c) a dead reckoning system having a distance traveled sensor interface and a heading sensor interface, wherein the dead reckoning component receives distance-traveled data from the distance-traveled sensor and heading data from the heading sensor and generates a first set of vehicle position data and a first set of vehicle heading data; (d) a reference vehicle position system in direct communication with the dead reckoning component, wherein the reference vehicle position system generates a second set of vehicle heading data and a second set of vehicle position data to the dead reckoning system; (e) a first computational means for determining if the vehicle is stationary; (f) a second computational means for generating an updated heading sensor bias; (g) a third computational means for generating a heading sensor bias drift rate; (h) a fourth computational means for integrating the first set of vehicle heading data and the second set of vehicle heading data into an integrated vehicle heading; (i) a fifth computational means for integrating the first set of vehicle position data and the second set of vehicle position into an integrated vehicle heading; (j) a sixth computational means for calculating an integrated vehicle heading correction using the estimated bias drift rate to compensate for integrated vehicle heading errors induced by heading sensor bias drift and an integrated vehicle position correction using the first integrated vehicle heading correction to compensate for integrated vehicle position errors induced by heading sensor bias drift; and (k) a seventh computational means for calculating a corrected vehicle heading and position.