RESTRAINT OF AXIAL VIBRATION

摘要

PURPOSE:To suppress shaft vibration without causing damage to the speed control responsive performance by lowering the control gain of a speed system when the vibration frequency of a rotating shaft gets approximately equal to the resonance frequency. CONSTITUTION:A speed controller 32 outputs a current command I0 according to the difference between a speed command N0 and a detection rotating speed N of a rotating shaft. A current controller 34 outputs a torque command tau0 according to the difference between the current command I0 and Motor current I. A motor is driven according to the difference between the torque command tau0 and a torque detection value tau. On the other, a function generator 30 outputs a command to lower the gain of the speed controller 32 when the detection rotating speed N gets close to the rotating speed at which shaft resonance would be caused. In this way, the shaft vibration can be suppressed without causing damage to the speed control responsive performance in the operational region where the shaft resonance is out of the question.