A feedback control system is shown in Fig. 6.105. The closed-loop system is specified to have an overshoot of less than 30% to a step input.
(a) Determine the corresponding PM specification in the frequency domain and the corresponding closed-loop resonant-peak value Mr . (See Fig. 6.38.)
(b) From Bode plots of the system, determine the maximum value of K that satisfies the PM specification.
(c) Plot the data from the Bode plots [adjusted by the K obtained in part (b)] on a copy of the Nichols chart in Fig. 6.84, and determine the resonant peak magnitude Mr. Compare that with the approximate value obtained in part (a). (d) Use the Nichols chart to determine the resonant-peak frequency ωr and the closed-loop bandwidth.
