Block diagrams in TikZ format

Background

Anton created a set of block diagrams in ps format, where text elements can be changed using \psfrag in latex. This page provides ports of these block diagrams to TikZ. The reason for creating these ports were:

• The traditional latex compilation, using dvi and ps as middle formats, is widely being replaced with pdflatex and there is no equivalent to psfrag in pdflatex.
• TikZ allows for changes not only of text, but also of the graphics, directly in the .tex document.

• Matlab graphics can be exported to TikZ. The format can therefore cater for all graphics needs.

Practical

A simple Example

TikZ is a programming language and a TikZ picture is a set of code. The below minimal example shows a .tex document, demonstrating the inclusion of a TikZ block diagram:

\documentclass{pm}
\usepackage{tikz}
\usetikzlibrary{narrow}
\tikzset{>=narrow}
\begin{document}
Figure~\ref{fig:blocks} shows an example block diagram.
\begin{figure}
\centering
%
\begin{tikzpicture}
\small                                                                           
\tikzstyle{block} = [draw,rectangle,minimum size=8mm,node distance=25mm]
\tikzstyle{sum} = [draw, circle,node distance=8mm,inner sep=0mm,minimum size=4mm]
\node[block](G1){$G_1$};
\node[block,below of=G1,yshift=10mm](G2){$G_2$};
\node[sum,left of=G1,xshift=-3mm](s){$s$};
\node[coordinate,left of=s](input){};
\node[coordinate,right of=G1,xshift=6mm](output){};
\draw[->](input)--node[above,near start](){$R$}(s);
\draw[->](s)--(G1);
\draw[->](G1)--node[above,near end](){$Y$}(output);
\draw[->]([xshift=5mm]G1.east)|-(G2);
\draw[->](G2)-|(s);
\end{tikzpicture}
%
\caption{This is a block diagram.\label{fig:blocks}}
\end{figure}
\end{document}

The above code generates a picture that looks like this:

If you think the TikZ code (\begin{tikzpicture to \end{tikzpicture}) clutters the .tex file, it can be placed in a separate file, e,g. mypicture.tikz, and inserted in the .tex file using the the command \input{mypicture.tikz}, which simply places the content of mypicture.tikz at the location of the commend.

The arrow style >=narrow is local to the department. If you do not have access to it on your computer, you may use >=latex instead, or download the file defining the style.

Scaling the block diagrams

A simple way to change the size, when including a TikZ picture is to add an extra argument to \begin{tikzpicture}. Here are some examples:

\begin{tikzpicture}[scale=0.6]

The above scales edges, but not the nodes, neither text.

\begin{tikzpicture}[scale=0.6, every node/.style={scale=0.6}]

The above scales both nodes and edges, but not text.

Some people think the default line width is a bit thin. This can easily be changed by adding e.g. thick to the argument list; \begin{tikzpicture}[thick]. (Arguments are comma-separated.)

More info

A lot can be found on online forums. There also exists an extremely well-written (but long!) manual for TikZ and a much more compact minimal introduction.

Note that you can draw almost anything in TikZ, not only block diagrams.

Block diagrams

Feedback systems

feedback0

\begin{tikzpicture}
\small                                                                           
\tikzstyle{block} = [draw, rectangle,minimum size=8mm,node distance=25mm]
\tikzstyle{sum} = [draw,circle,node distance=8mm,inner sep=0mm,minimum size=4mm]
\node[block](G1){$G_1$};
\node[block,below of=G1,yshift=10mm](G2){$G_2$};
\node[sum,left of=G1,xshift=-3mm](s){$s$};
\node[coordinate,left of=s](input){};
\node[coordinate,right of=G1,xshift=6mm](output){};
\draw[->](input)--node[above,near start](){$R$}(s);
\draw[->](s)--(G1);
\draw[->](G1)--node[above,near end](){$Y$}(output);
\draw[->]([xshift=5mm]G1.east)|-(G2);
\draw[->](G2)-|(s);
\end{tikzpicture}

feedback1

\begin{tikzpicture}
\small
\tikzstyle{block} = [draw, rectangle,minimum size=8mm,node distance=25mm]
\tikzstyle{sum} = [draw,circle,node distance=8mm,inner sep=0mm,minimum size=4mm]
\node[block](G1){$G_1$};
\node[block,right of=G1,xshift=-6mm](G2){$G_2$};
\draw[->](G1)--node[above](U){$U$}(G2);
\node[block,below of=U,yshift=10mm](G3){$G_3$};
\node[sum,left of=G1,xshift=-6mm](s){$s$};
\node[coordinate,left of=s](input){};
\node[coordinate,right of=G2,xshift=6mm](output){};
\draw[->](input)--node[above,near start](){$R$}(s);
\draw[->](s)--node[above](){$E$}(G1);
\draw[->](G2)--node[above,near end](){$Y$}(output);
\draw[->]([xshift=5mm]G2.east)|-(G3);
\draw[->](G3)-|(s);
\end{tikzpicture}

feedback1b

\begin{tikzpicture}
\small
\tikzstyle{block} = [draw, rectangle,minimum size=8mm,node distance=25mm]
\tikzstyle{sum} = [draw,circle,node distance=8mm,inner sep=0mm,minimum size=4mm]
\node[block](G1){$G_1$};
\node[block,right of=G1,xshift=-6mm](G2){$G_2$};
\draw[->](G1)--node[above](U){$U$}(G2);
\node[block,below of=U,yshift=10mm](G3){$G_3$};
\node[sum,left of=G1,xshift=-6mm](s){$s$};
\node[coordinate,left of=s](input){};
\node[coordinate,right of=G2,xshift=6mm](output){};
\draw[->](input)--node[above,near start](){$R$}(s);
\draw[->](s)--node[above](){$E$}(G1);
\draw[->](G2)--node[above,near end](){$Y$}(output);
\draw[->]([xshift=5mm]G2.east)|-(G3);
\draw[->](G3)-|(s);
\node[coordinate,above of=G2,yshift=2mm](input2){};
\draw[->](input2)--node[right,near start](){$V$}(G2);
\end{tikzpicture}

feedback1c

\begin{tikzpicture}
\small
\tikzstyle{block} = [draw,rectangle,minimum size=8mm,node distance=25mm]                                 
\tikzstyle{sum} = [draw,circle,node distance=8mm,inner sep=0mm,minimum size=4mm]
\node[block](G1){$G_1$};
\node[block,right of=G1,xshift=-6mm](G2){$G_2$};
\draw[->](G1)--node[above](U){$U$}(G2);
\node[draw,rectangle,below of=U](G3){$G_3$};
\node[sum,left of=G1,xshift=-6mm](s){$s$};
\node[coordinate,left of=s](input){};
\node[coordinate,right of=G2,xshift=6mm](output){};
\draw[->](input)--node[above,near start](){$R$}(s);
\draw[->](s)--node[above](){$E$}(G1);
\draw[->](G2)--node[above,near end](){$Y$}(output);
\draw[->]([xshift=5mm]G2.east)|-(G3);
\draw[->](G3)-|(s);
\end{tikzpicture}

feedback1d

feedback1e

\begin{tikzpicture}
\small
\tikzstyle{block} = [draw, rectangle,minimum size=8mm,node distance=25mm]
\tikzstyle{sum} = [draw,circle,node distance=8mm,inner sep=0mm,minimum size=4mm]
\node[block](G1){$G_1$};
\node[block,right of=G1,xshift=-6mm](G2){$G_2$};
\draw[->](G1)--node[above](U){}(G2);
\node[block,below of=U,yshift=10mm](G3){$G_3$};
\node[coordinate,right of=G2,xshift=6mm](output){};
\draw[->](G2)--node[above,near end](){}(output);
\draw[->]([xshift=5mm]G2.east)|-(G3);
\node[coordinate,left of=G1](turn){};
\draw[->](G3)-|(turn)--(G1);
\end{tikzpicture}

feedback2

feedback3

feedback4

feedback5

feedback6

feedback7

feedback8

feedback9

feedback10

feedback11

Other regulator structures

cascade1

cascade2

cascadeff

fbff1

fbff2

fftf

ffss

2DOF

smith1

smith2

Miscellaneous other

parallel

nyquist

openloop1

openloop1b

openloop2

openloop2c

dist1

dist2

dist3

State feedback and observers

statefeed1

statefeed2

statefeed4

statefeed5

statefeed6