A unity-feedback loop has the open-loop transfer function G(s) = 4(s + 5)/(s(s + 2)). What is the system type N?
Steady-state error & PID control worksheet with answers
1.Easy
G(s) = 4(s + 5)/(s(s + 2))
N =
2.Easy
A unity-feedback loop has the open-loop transfer function G(s) = 20(s + 3)/(s(s + 2)). Find the velocity error constant Kv.
G(s) = 20(s + 3)/(s(s + 2))
Kv =
3.Medium
A unity-feedback loop with G(s) = K/(s(s + 1)) must follow the ramp r(t) = 10t with a steady-state error of 0.01. Find the gain K.
G(s) = K/(s(s + 1))r(t) = 10tess = 0.01
K =
4.Medium
A unity-feedback loop has G(s) = K/((s + 2)(s + 5)). Find the gain K that gives a steady-state error of 2 % for a step input.
G(s) = K/((s + 2)(s + 5))ess = 2 %
K =
5.Hard
A proportional controller K drives the plant G(s) = 2/(s(s + 6)) in a unity-feedback loop. Find the gain K that gives the closed loop a damping ratio ζ = 0.6.
G(s) = 2/(s(s + 6))ζ = 0.6
K =
6.Hard
A proportional controller K = 50 drives the plant G(s) = 1/(s(s + 10)) in a unity-feedback loop. Find the peak time tp of the step response.
G(s) = 1/(s(s + 10))K = 50
tp = s
Answer key
- 1. N = 1
- 2. Kv = 30
- 3. K = 1000
- 4. K = 490
- 5. K = 12.5
- 6. tp = 0.6283 s
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