| 摘要 |
PURPOSE:To obtain an offset drift correction apparatus in which the angular- velocity offset of a gyro is corrected in real time by estimating the offset drift level of a gyro sensor and correcting the output of the gyro sensor. CONSTITUTION:When the zero-poing level, i.e. the offset level, of a gyro sensor 1 and the initial value of the output Cn of an adaptive filter 5 are within threshold value X of a judgment means 3, the difference between the output of the sensor 1 and the output Cn which is estimated at this time becomes an error amount excluding a time when a moving body is turning. Consequently, the error amount is averaged by a smoothing means 2, and the output Cn is renewed only when it is judged by the means 3 that the moving body is not turning. Then, the offset level of the sensor 1 can be estimated. That is to say, a corrected angular velocity in which the estimated offset level is subtracted in real time from the output of the sensor 1, can be regarded as a precise angular velocity. In addition, when the threshold value X of the means 3 is made large and the correction gain of the filter 5 is lowered, it is possible to follow a drift while the moving body is turning even when the control accuracy is worsened a little. |
