| 摘要 |
<p>A calculating member carries out Fourier analysis of a vibrational acceleration to calculate a maximum acceleration and frequency thereof. The calculating member then compares the maximum acceleration with a threshold value, and when the acceleration exceeds the threshold value, the calculating member calculates a k-value and phase information, and stores each calculated value. When retrying is selected, the calculating member determines a type of a current chatter vibration from the phase information, determines the existence of a chatter vibration which is different from the determined chatter vibration, and calculates each new phase information according to the determined chatter vibration and an existence of a different chatter vibration which had been generated before generation of the current vibration. The calculating member then calculates a k1-value from new phase information, calculates the optimum rotation speed by using the k1-value, and changes the rotation speed to the optimum rotation speed.</p> |
