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.

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
r(t) = 10+K = 42s + 10y(t)−

A proportional controller K = 4 drives the plant G(s) = 2/(s + 10) in a unity-feedback loop. A step of size 10 is applied. Find the final value of the output y(∞).

G(s) = 2/(s + 10)K = 4r = 10
y(∞) =
2.Easy
r(t) = 5+K = 32s + 10y(t)−

A proportional controller K = 3 drives the plant G(s) = 2/(s + 10) in a unity-feedback loop. A step of size 5 is applied. Find the final value of the output y(∞).

G(s) = 2/(s + 10)K = 3r = 5
y(∞) =
3.Medium
r(t) = 1 + 1t+2(s + 1)s(s + 1)(s + 4)C(s)−

The input r(t) = 1 + 1t (a step plus a ramp) is applied to a unity-feedback loop with G(s) = 2(s + 1)/(s(s + 1)(s + 4)). Find the steady-state error ess.

G(s) = 2(s + 1)/(s(s + 1)(s + 4))r(t) = 1 + 1t
ess =
4.Medium
R(s)+K = 9210s + 1C(s)−

A process G(s) = 2/(10s + 1) is controlled by a proportional gain K = 9 in a unity-feedback loop. Find the steady-state error ess for a step, as a percentage of the step size.

G(s) = 2/(10s + 1)K = 9
ess = %
5.Hard
R(s)+K = 405s(s + 6)C(s)−

A proportional controller K = 40 drives the plant G(s) = 5/(s(s + 6)) in a unity-feedback loop. Find the peak time tp of the step response.

G(s) = 5/(s(s + 6))K = 40
tp = s
6.Hard
R(s)+K = 252s(s + 10)C(s)−

A proportional controller K = 25 drives the plant G(s) = 2/(s(s + 10)) in a unity-feedback loop. Find the peak time tp of the step response.

G(s) = 2/(s(s + 10))K = 25
tp = s

Answer key

  1. 1. y(∞) = 4.444
  2. 2. y(∞) = 1.875
  3. 3. ess = 2
  4. 4. ess = 5.263 %
  5. 5. tp = 0.2273 s
  6. 6. tp = 0.6283 s

Full step-by-step solutions: practise this topic on examproblems.com.