| 摘要 |
PURPOSE:To sense a motor speed with a high accuracy, by providing the memory storing the correction value for correcting the dispersion around a true period, which is exhibited by the periods of the respective pulse signals obtained from an encoder, and by reading out the correction value from the memory every the pulse signal when measuring the period of the pulse signal obtained from the encoder, and further, by correcting the period of the pulse signal with the correction value. CONSTITUTION:In a part 21 for sensing an encoder pulse signal, the encoder pulse signal is specified, and the value corresponding to the specified pulse signal is read out from a ROM 22. Then, the value is inputted to a speed sensing part 11, and the error of the period of the specified pulse signal is compensated. In the speed sensing part 11, a counting value of the period is converted to a pulse number NT corresponding to it. In the pulse number NT, the compensation of the dispersion in the periods of the encoder pulse signal is completed, and the pulse number NT is an accurate speed value. Thereby, since the dispersion of the respective measured periods of the encoder pulse signal is corrected, an accurate speed measurement can be performed. |
