| 摘要 |
PURPOSE:To prevent the stepout by adding altering frequency to the frequency of an inverter to control when the prescribed vibration is obtained by two or more vibration motors, thereby varying the voltage phase within the range of desired internal phase difference angle. CONSTITUTION:Signals of a driven side motor SM1 connected to an inverter IV and pickups PP1, PP2 of a reference motor SM2 are inputted to a phase difference detector PHD, and the deviation between the output and the set value is applied to a calculator IVA. At the frequency altering time the final value is represented by thetaE, the altering amount is by DELTAomega0, the period of adding DELTAomega0 is by Ta, the number of pole pairs is by (n), thetaE=Ta/n.omega0(rad) is calculated, the SW is turned ON during the obtained period Ta, DELTAomega0 is applied to the inverter frequency omega0 to control the IV, thereby generating the prescribed vibration. Accordingly, the internal phase difference angle of the motor does not increase at the frequency altering time to cause no stepout, thereby stably controlling it. |
