Calibration apparatus of angular velocity sensor in self-contained

Abstract

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 an angular-velocity detection unit for calculating an angular velocity from an output signal of the angular-velocity detection sensor; an integration unit for calculating a current heading of the vehicle by integrating the angular velocity and by adding the integrated angular velocity to the previous heading of the vehicle; a location and heading detection unit which estimates a location of the vehicle from the current heading calculated by the integration unit, 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 a heading correction unit for calculating a difference between the heading of the integration unit and the heading of the location and heading detection unit and integrating the difference over a predetermined distance to obtain an error per unit distance, for calculating the difference or the error per unit distance, as a correction value for correcting the current heading of the integration unit, and for feeding the correction value back to the intergration unit. The current heading of the integration unit is corrected by subtracting the correction value from the current heading of the integration unit.