\definecolor{lightblue}{HTML}{0087EF}
\tikzstyle{block} = [draw, fill=lightblue!13, rectangle,
    minimum height=3em, minimum width=6em]
\tikzstyle{sum} = [draw, fill=lightblue!13, circle, node distance=1cm]
\tikzstyle{input} = [coordinate]
\tikzstyle{output} = [coordinate]
\tikzstyle{pinstyle} = [pin edge={to-,thin,black}]

\tikzset{integrator/.pic={
\draw [draw,fill=lightblue!13](0,1.5em)rectangle(0.65em,-1.5em) (0.65em,1.5em)--(3.4em,0)--(0.65em,-1.5em);
}, dif/.pic={
\node at (0,0) [draw, fill=lightblue!13, draw,rectangle, minimum size=1.2cm] {$\displaystyle \frac{\mathrm{d}}{\mathrm{d}t}$};}}

\begin{tikzpicture}[auto, node distance=2cm,>=latex']
    \node [input, name=input] {};
    \node [sum, right of=input] (sum) {};
    \node [block, right of=sum] (controller) {Regulator};
    \node [block, right of=controller, pin={[pinstyle]above:Disturbances},
            node distance=3cm] (system) {System};
    \draw [->] (controller) -- node[name=u] {$u$} (system);
    \node [output, right of=system] (output) {};
    \node [below of=u] (integrator) {\pic [rotate=180]{integrator}};

    \draw [->] (input) -- node {$r$} (sum);
    \draw [->] (sum) -- node {$e$} (controller);
    \draw [->] (system) -- node [name=y] {$y$}(output);
    \draw [->] (y) |- (integrator);
    \draw [->] (integrator) -| node[pos=0.99] {$-$}
        node [near end] {$y_m$} (sum);
\end{tikzpicture}