Unformatted text preview: ω and K at the j-axis crossing. (b)(10). When K , the closed-loop system has a pole at 160 = 10 − = s . Calculate the location of the other two closed-loop poles. (c)(15). When , sketch the straight-line Bode plot (magnitude and phase). Using this plot, find the approximate gain margin in dB? What is the gain margin as an absolute number? Using this value of gain margin, what is the largest value of K just before instability occurs? 80 = K (d)(15). Find the phase margin when (You can use MATLAB here) ( i ) K =20. What is the damping ratio of the complex roots? ( ii ) K =40. What is the damping ratio in this case? ( iii ) If the phase margin decreases, what happens to percent overshoot?...
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- Spring '07
- Gain margin, j -axis crossing