Consider the continuous-time feedback system depicted in Figure P11.46(a) (a) U...

Consider the continuous-time feedback system depicted in Figure P11.46(a)

(a) Use the straight-line approximations to Bode plots developed in Chapter 6 to obtain a sketch of the log magnitude-phase plot of this system. Estimate the phase and gain margins from your plot (b) Suppose that there is an unknown delay within the feedback system, so that the actual feedback system is as shown in Figure P11.46

(b). Approximately what is the largest delay τ that can be tolerated before the feedback system becomes unstable? Use your results from part (a) for this calculation.

(c) Calculate more precise values of the phase and gain margins, and compare these to your results in part (a). This should give you some idea of the size of the errors that are incurred in using the approximate Bode plots.