| 摘要 |
PURPOSE:To continue synchronization control on rotation without switching the control to speed control by measuring in advance the deviated angle between a motor index and medium index which is obtained at every rotation and continuing the synchronization control by estimating the medium index generating position from the deviated angle when the medium index disappears. CONSTITUTION:The first time-lag measuring means 14 which measures the time lag T1 between a motor index and medium index and the second time-lag measuring means 16 which measures the time lag T2 between the motor index and a target index are provided and the time difference Te between the measured time lags T1 and T2 is calculated. In addition, a motor controlling means 20 which controls a motor 10 so as to make the time difference Te calculated by a time difference measuring means 18 zero is also provided. Moreover, an estimating means 26 which is incorporated in the means 18 and estimates the time lag T1 on the basis of the deviated angle of a deviated angle calculating means 22 and makes the means 18 to calculate the time lag Te from the estimated time lag T1 when a medium index discriminating means 23 discriminates that no medium index exists is also provided. |
