Patent ID: 7835878

Claim:
A system for detecting a travel angle of a mobile object having a detector installed in the mobile object to produce outputs indicative of angular velocity in response to displacement of the mobile object successively, comprising: a reader that reads the outputs produced by the detector successively; a calibration value determiner that determines one of the outputs as a provisional calibration value indicative of zero-point; an integrator that calculates a difference between the provisional calibration value and each of the successive outputs produced after the provisional calibration value and calculates an integrated value of the difference; a variation width calculator that calculates a variation width of the read successive outputs; a discriminator that discriminates whether the calculated integrated value and variation width are within predetermined permissible ranges; a calibration value corrector that determines the mobile object is in static condition when the calculated integrated value and variation width are discriminated to be within the permissible ranges, and corrects the calibration value by an average value of the integrated values; and a travel angle detector that calibrates the outputs of the detector by the corrected calibration value and detects the travel angle of the mobile object based on the calibrated outputs of the detector.