Steady-state error & PID control worksheet with answers

Free printable Steady-state error & PID control worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
R(s)+10(s + 2)(s + 4)C(s)−

A unity-feedback loop has the open-loop transfer function G(s) = 10/((s + 2)(s + 4)). Find the position error constant Kp.

G(s) = 10/((s + 2)(s + 4))
Kp =
2.Easy
R(s)+20s(s + 2)(s + 5)C(s)−

A unity-feedback loop has the open-loop transfer function G(s) = 20/(s(s + 2)(s + 5)). Find the velocity error constant Kv.

G(s) = 20/(s(s + 2)(s + 5))
Kv =
3.Medium
r(t) = 5·t²/2+4(s + 4)s²(s + 4)C(s)−

The parabolic input r(t) = 5·t²/2 is applied to a unity-feedback loop with G(s) = 4(s + 4)/(s²(s + 4)). Find the steady-state error ess.

G(s) = 4(s + 4)/(s²(s + 4))r(t) = 5·t²/2
ess =
4.Medium
r(t) = 10 + 2t+4s(s + 4)(s + 10)C(s)−

The input r(t) = 10 + 2t (a step plus a ramp) is applied to a unity-feedback loop with G(s) = 4/(s(s + 4)(s + 10)). Find the steady-state error ess.

G(s) = 4/(s(s + 4)(s + 10))r(t) = 10 + 2t
ess =
5.Hard
r(t) = 2t+5 + 10/s10(s + 1)(s + 10)C(s)−

A PI controller C(s) = 5 + 10/s drives the plant G(s) = 10/((s + 1)(s + 10)) in a unity-feedback loop. Find the steady-state error ess for the ramp input r(t) = 2t.

C(s) = 5 + 10/sG(s) = 10/((s + 1)(s + 10))r(t) = 2t
ess =
6.Hard
r(t) = 5t+1 + 1/s4(s + 1)(s + 2)C(s)−

A PI controller C(s) = 1 + 1/s drives the plant G(s) = 4/((s + 1)(s + 2)) in a unity-feedback loop. Find the steady-state error ess for the ramp input r(t) = 5t.

C(s) = 1 + 1/sG(s) = 4/((s + 1)(s + 2))r(t) = 5t
ess =

Answer key

  1. 1. Kp = 1.25
  2. 2. Kv = 2
  3. 3. ess = 1.25
  4. 4. ess = 20
  5. 5. ess = 0.2
  6. 6. ess = 2.5

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