| 摘要 |
PURPOSE:To relinquish rapidly a residual deviation of a variable to be controlled by detecting a low frequency component of a deviation signal by an LPF and multiplying the amplified signal with a high frequency signal to generate a dither signal having an amplitude in response to the deviation. CONSTITUTION:In order to cancel the residual deviation, a dither control circuit comprising an LPF4, a nonlinear amplifier 5, an oscillator 6 generating a cosine wave of constant amplitude and constant frequency and a multiplier 7 is provided. The LPF4 excludes the cosine wave component included in a deviation signal (e), extracts a signal e' after smoothing the signal (e) and the amplifier 5 has a role multiplying the signal e' by d-times. On the other hand, the cosine wave of the unit amplitude from the oscillator 6 is multiplied by the signal de' by the multiplier 7 and converted into a signal Xd subjected to amplitude modulation. The signal Xd obtained in this way is superimposed on the signal (e) as a dither signal, the result is added to a servo amplifier 1 and nonlinear friction included in the servo motor 2 is linearized. |
