試題詳解

6. Which of the following statements are true? 
(A) Given the characteristic equation 3s²+ 5s+k = 0 of a linear control system, increasing the value of k will decrease the frequency of oscillation of the system.
(B) can be approximated bysince the pole at -20 is much larger than the dominant poles at O and -1.
(C) For a stable open-loop system with a perfect model P(s), it is always possible to have a stable and causal feedforward controller F(s) such that P(s)F(s) = 1.
(D) The maximum overshoot of is possibly exceed 100 percent when and T are all positive.
(E) If a unity-feedback control system type is 2, then it is certain that the steady-state error of the system to a step or a ramp input will be zero.