| 摘要 |
PURPOSE:To prevent a trouble including a runaway of a stage, etc., by monitoring the varied amount of a resonance peak and thereby, preventing the oscillation of a control system. CONSTITUTION:The feedback control is carried out to control a controlling object system 23 in response to the difference between the target value and a controlled amount via a compnesator 21 like a PID and a notch filter 22. A BPF 24 detects the signal of a prescribed frequency band from the controlled amount with high sensitivity. The frequency band is coincident with the frequency of the resonance peak and therefore the output of the BPF 24 shows the level of the resonance peak. A comparator 25 compares the level Vm with the reference value Vr. Then, an error signal is produced when the Vm is larger than the Vr. Thus, it is possible to prevent the oscillation of a control system and also to prevent the troubles like the runaway of a stage. |
