AZIMUTH DETECTOR WITH OFFSET CORRECTING FUNCTION

摘要

PURPOSE:To detect the accurate azimuth of a moving body by storing and reading out the time variation coefficient of offset and using the preceding offset value and the read-out time variation coefficient to obtain the offset of a turning angular speed sensor output and correcting the offset. CONSTITUTION:A locator 1 counts pulses of the output signal from a speed sensor 41 to obtain the rotational frequency of a wheel and multiplies outputted count output data in a multiplier by a prescribed constant indicating the distance per count to calculate covered distance output data per unit time. The relative change of the azimuth of a vehicle is obtained from a gyro 43, and azimuth, output data of the vehicle is obtained in accordance with this relative change and absolute azimuth output data of a terrestrial magnetism sensor 42. The gyro 43 is preliminarily tested to store a time variation (m) of offset in an offset memory 21. This variation (m) is retrieved at any time during running and is used to correct the offset value.