- #1

- 148

- 0

Basically, the open-loop transfer function of the system is

[tex]\frac { 3s+0.5 }{ s({ s }^{ 2 }+3s+8) } [/tex]

The closed-loop system is

[tex]\frac { 3s+0.5 }{ { s }^{ 3 }+{ s }^{ 2 }+11s+0.5 } [/tex]

I found the values of the steady-state errors, but the problem is that the numbers don't match with the simulation. I'm pretty sure there is something wrong with my code since the errors for both step and ramp responses are close to 0. The calculations show 0.5 and infinity respectively.

Here is my working and plots.

Here is my code:

Code:

```
sys1 = 3 + tf(0.5.*[1], [1 0]);
sys2 = tf([1], [1 3 8]);
sys = feedback(sys1*sys2, 1)
subplot(1,2,1)
step(sys)
hold on
step(tf(1))
hold off
sys3 = tf([1], [1 0]);
subplot(1,2,2)
step(sys*sys3)
title('Ramp Response')
hold on
step(sys3)
hold off
```