| 摘要 |
PURPOSE:To reduce the effect of disturbance high in magnitude of signal amplitude and to minimize a following error regardless of the level of the disturbance amplitude, by giving nonlinear control to a loop gain in response to the output given from a means which detects an abnormal disturbance. CONSTITUTION:An output signal given from a control subject is detected by a detector 10 and applied to an adder 12 after amplification 11. The output signal received by the adder 12 undergoes addition/subtraction with the prescribed target value. Thus an error signal is detected and then divided into two parts. One of these two divided error signals is supplied to an amplification degree controllable amplifier 13; while the other error signal is supplied to a filter 14 which transmits an abnormal disturbance. The amplitude of the abnormal disturbance signal passed through the filter 14 is detected by an amplitude detector 15 and supplied to a nonlinear amplifier 16. The amplifier 16 gives the linear amplitude to the disturbance signal when it has a level higher than the threshold value. Then the voltage of a fixed level is delivered when the disturbance signal has a level less than the threshold value. Both the amplifier 13 and a central frequency controllable phase compensator 17 are controlled by the output of the amplifier 16. Then the loop gain is controlled according to the output of the amplifier 16. Thus it is possible to reduce the effect of the disturbance which is high in signal amplitude. |
