VEHICLE ROTATIONAL-ANGLE CALCULATING APPARATUS

摘要

A first sensor outputs a signal representing an angular rate of a vehicle body. A second sensor outputs a signal representing a direction of the vehicle body. The output signal of the first sensor is integrated to generate a signal representing a tentative rotational angle of the vehicle body. First data pieces are generated which represent temporally spaced samples of the output signal of the second sensor respectively. Second data pieces are generated which represent temporally spaced samples of the tentative rotational angle signal respectively. Two first data pieces are selected from among the first data pieces. Calculation is given of a time interval between the occurrence moments of the selected two first data pieces. Two second data pieces are selected from among the second data pieces. Calculation is given of a direction difference between directions represented by the selected two first data pieces. Calculation is given of a rotational-angle difference between tentative rotational angles represented by the selected two second data pieces. An amount of offset in the output signal of the first sensor is calculated in response to the calculated time interval and the calculated rotational-angle difference in cases where the calculated direction difference is equal to or smaller than a predetermined direction difference. The output signal of the first sensor is corrected into an offset-free signal in response to the calculated offset amount. The offset-free signal is integrated to generate a signal representing a final rotational angle of the vehicle body.