The Integral Absolute value Error (IAE) and the Integral Squared Error (ISE) is to be analysed.
A PID Controller is given as follows:
\begin{gather} C(s)=K_p+K_i\frac{1}{s}+K_ds \end{gather} where $K_p=0.07847$, $K_i=0.03587$ and $K_d=0.04291$.
The transfer function of the controlled system is: \begin{gather} G(s) = \frac{1}{s^2+s+1} \end{gather}
Now as a feedback loop I have following:
Calculating the overall Transfer function $F(s)$ we get:
$$ F(s) = \frac{0.04291s^2+0.07847s+0.03587}{s^3+1.043s^2+1.078s+0.03587} $$
The step response looks like:
Now I wanted to find the Integral Absolute value Error (IAE) and the Integral Squared Error (ISE). By researching google I came to know the principle behind it and I also saw the formulas but how really to mathmetically solve it.
For example to solve for ISE for $W(s)$ as step response in frequency domain: \begin{gather} e(s)=w(s)-y(s) \\ \\ e(s) = w(s)-(F(s)w(s)) \\ \\ e(s) = \frac{1}{s}-(\frac{F(s)}{s}) \end{gather}\begin{gather} e(s)=w(s)-y(s) \\ \\ e(s) = w(s)-(F(s)w(s)) \\ \\ e(s) = \frac{1}{s} - \left(\frac{F(s)}{s}\right) \end{gather}
Now I replace $F(s)$ and solve for $e(s)$ ??
After that integrate from $0$ to infinity to the $e(s)^2$?? I don't get it. How am I supposed to get the tuned value for $K_p$, $K_i$ and $K_d$?
Matlab code is here.