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Calibration apparatus of angular velocity sensor in self-contained navigational system

  • US 5,115,238 A
  • Filed: 04/02/1990
  • Issued: 05/19/1992
  • Est. Priority Date: 04/07/1989
  • Status: Expired due to Term
First Claim
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1. A calibration apparatus of an angular-velocity detection sensor for detecting a heading of a vehicle which is used in a self-contained navigational system, comprising:

  • angular-velocity detection means for calculating an angular velocity from an output signal of said angular-velocity detection sensor;

    integration means for calculating a current heading of the vehicle by integrating said angular velocity and by adding the integrated angular velocity to the previous heading of the vehicle;

    location and heading detection means which estimates a location of the vehicle from said current heading calculated by said integration means, a heading obtained by a magnetic sensor and from a distance obtained by a distance sensor and which compares the estimated location with road network data obtained from a road map memory to obtain an estimated heading of the vehicle; and

    heading correction means for calculating a difference between said current heading of said integration means and said estimated heading of said location and heading detection means and integrating said difference over a predetermined distance to obtain an error per unit distance, for calculating said difference or said error per unit distance, as a correction value for correcting said current heading of said integration means, and for feeding said correction value back to said integration means;

    said current heading of said integration means being corrected by subtracting said correction value from said current heading of said integration means.

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