| 摘要 |
PURPOSE:To prevent the abnormal vibration of a machine system by enabling to vary a speed command value in case of a speed command in response to the specific frequency range for inducing the abnormal vibration. CONSTITUTION:When a speed command Vi is the value within a speed command range (VL-VH) corresponding to the frequency range to be avoided for continuous operation, a discriminator 6 closes an analog switch 7b and opens analog switch 7a. Thus, the upper limit value VH or the lower limit value VL of an avoiding range setter 4 is inputted through a converter 8 and the switch 7b to an analog/digital converter 2. Thus, when the speed command in response to the frequency for generating the abnormal vibration is applied, it can be converted to the speed commaned of other value, thereby preventing the abnormal vibration of a machine system. |
