In the system shown below, what is steady state error in unit ramp response? [Figure description: A block diagram. R(s) enters a summing junction (+ at input, - at feedback) followed by a forward block 1/(s^2 (s+12)) giving C(s). The output C(s) is fed back through three parallel feedback paths that are summed: a block 5(s+1)/(s+5), a block +1, and a block -1, all returning to the negative input of the summing junction.]
- A. 5/4
- B. 4/5
- C. 3/5
- D. 5/5
Answer: B. 4/5
Explanation: Feedback H(s) = 5(s+1)/(s+5); error E = R − C. For a unit ramp input ess = lim s→0 (1/s)[1 + G(H−1)]/(1 + GH) = 12/15 = 4/5.