Question

Consider the following control system: R + Let G(s) s +23-3 and H(s) K where K is some positive constant. The transfer function H(s) can be considered a proportional feedback controller. (a) Examine the behavior of the system for different values of K. Try the values K 2, 4, 8. In each case, plot the pole-zero map of the closed-loop system and examine the step response. Comment on the stability of the system. Find the value of K for which the system becomes marginally stable (the poles are on the imaginary axis). (b) Let K2 where Ki and K, are positive constants. The feedback controller in this case is called a proportional-integral (PI) controller. Set K-1 and K-3, 4, 8. Comment on the effect of changing Ki on the system. Find the value of Ki for which the system becomes marginally stable. (c) Look at the plots for parts (a) and (b) for which the system is stable. What can you say about the final value of the system response? How does the integral controller affect the final value?

Answer 1

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