How to use tikz for sensor and actuator diagram

Question

The code is below.

\documentclass[12pt,letterpaper]{article}    
\usepackage[left=20mm,top=30mm,bottom=30mm,right=20mm]{geometry}
\usepackage{tikz}  % for drawing pictures
\usetikzlibrary{arrows.meta,
                chains,
                positioning,
                quotes,
                shapes.geometric, arrows}
\begin{document}
\begin{center}
\begin{tikzpicture}[auto, 
                node distance = 15mm and 19mm,
                start chain = going right,
                arr/.style = {->},>=Latex,
                block/.style = {draw, minimum height=3em, minimum
                width=4em,align=center,fill=blue!20},
                sum/.style = {circle, draw, node contents={}},

                        ]
                \begin{scope}[nodes={on chain, join=by arr}]

                \coordinate (in);
            \node (n4) [block] {$K_m = 2 \times 10^{-1}$ \\ $N mV^{-1}$};

        \node (n5) [block] {$K_s = 5 \times 10^{-2}$ \\ $rad \hspace{1mm} N^{-1} m^{-1}$};
            \coordinate (out);

         \path (n4) to [below, pos=0.5,&quot;$T$&quot;] (n5)   (out) ;
          \path (n4) to [below, pos=0.5,&quot;$V$&quot;]  (in) ;

            \path (n5) to [below, pos=0.5,&quot;$\theta$&quot;]  (out) ;


\end{tikzpicture}
\end{center}
\end{document}

This picture below is what I got from code above.

This below is what I want to achieve.

just add labels belov of nodes and missed labels above/below of arrows ... — Zarko, Jan 19 '23 at 11:25
Fir you need to make your MWE compilable ... missed are begin{document} etc. To node ad label=below:text. I will write an answer ASAP — Zarko, Jan 19 '23 at 11:32

Zarko · Accepted Answer · 2023-01-20T08:28:39.823

Sorry, I hadn't spare time earlier ...

A possible solution can be:

\documentclass[12pt,letterpaper]{article}
\usepackage[hmargin=20mm,vmargin=30mm]{geometry}
\usepackage{siunitx}
\usepackage{tikz}  % for drawing pictures
\usetikzlibrary{arrows.meta,
                decorations.markings,
                positioning,
                quotes,
                shapes.geometric}
\begin{document}
    \begin{center}
    \begin{tikzpicture}[auto,
node distance = 1mm and 19mm,
 block/.style = {draw, fill=blue!20,
                 minimum height=3em, minimum width=4em, align=center,
                 label=below:#1
                 },
   sum/.style = {circle, draw, node contents={}},
%
   arr/.style = {-{Stealth[scale=1.6]}},
   ->-/.style = {decoration = {markings,mark=at position 0.5
                               with {\arrow[scale=1.6]{Stealth}}},
                 postaction={decorate}},
every edge quotes/.append style = {anchor=center, align=center}
                        ]
\coordinate (in);
\node (n4) [block=Motor,  right=of in] {$K_m=2\times 10^{-1}$ \ \unit{N mV^{-1}}};
\node (n5) [block=Spring, right=of n4] {$K_s=5\times 10^{-2}$ \ \unit{\radian\per\newton\per\metre}};
\coordinate[right=of n5] (out);
\draw       (in) edge [->-,"$V$\ Volts"] (n4)
            (n4) edge [->-,"$T$\ \unit{\newton\meter\second}"]   (n5)
            (n5) edge [arr, "$\theta$\ rad"]  (out);
    \end{tikzpicture}
    \end{center}
\end{document}

Addendum: A case when nodes "block" are in chain.

\usepackage[hmargin=20mm,vmargin=30mm]{geometry}
\usepackage{siunitx}
\usepackage{tikz} 
\usetikzlibrary{arrows.meta,
                chains,                % added
                decorations.markings,
                positioning,
                quotes,
                shapes.geometric}
\begin{document}
    \begin{center}
    \begin{tikzpicture}[auto,
node distance = 1mm and 19mm,
  start chain = going right,
    CB/.style = {draw, fill=blue!20,   % ChainBlock
                 minimum height=3em, minimum width=4em, align=center,
                 on chain,             % added
                 label=below:#1
                 },
   sum/.style = {circle, draw, node contents={}},
%
   arr/.style = {-{Stealth[scale=1.6]}},
   ->-/.style = {decoration = {markings,mark=at position 0.5
                               with {\arrow[scale=1.6]{Stealth}}},
                 postaction={decorate}},
every edge quotes/.append style = {anchor=center, align=center}
                        ]
\coordinate[on chain] (in);  % added option "on chain"
\node (n4) [CB=Motor] {$K_m=2\times 10^{-1}$ \ \unit{N mV^{-1}}};
\node (n5) [CB=Spring]{$K_s=5\times 10^{-2}$ \ \unit{\radian\per\newton\per\metre}};
\coordinate[on chain] (out); % added option "on chain"
\draw       (in) edge [->-,"$V$\ Volts"] (n4)
            (n4) edge [->-,"$T$\ \unit{\newton\meter\second}"]   (n5)
            (n5) edge [arr, "$\theta$\ rad"]  (out);
    \end{tikzpicture}
    \end{center}
\end{document}

Result is the same as before.

As I'm curious: how can we have the same stealth for the very last arrow? — NBur, Jan 19 '23 at 15:41
@NBur, me too ... ah in arr style I forgot to add the same scaling Stealth as at ->-. Corrected now. Thank you very much to point me on this. — Zarko, Jan 19 '23 at 16:04

score 3 · Answer 2 · answered Jan 19 '23 at 11:51

I added the siunitx package and the calc library.

\documentclass[12pt,letterpaper]{article}    
\usepackage[left=20mm,top=30mm,bottom=30mm,right=20mm]{geometry}
\usepackage{tikz}  % for drawing pictures
\usetikzlibrary{arrows.meta,
  calc,
  chains,
  positioning,
  quotes,
  shapes.geometric, arrows}
\usepackage{siunitx}
\begin{document}
  \begin{center}
    \begin{tikzpicture}[auto, 
      node distance = 15mm and 19mm,
      start chain = going right,
      arr/.style = {->},>=Latex,
      block/.style = {draw, minimum height=3em, minimum
        width=4em,align=center,fill=blue!20},
      sum/.style = {circle, draw, node contents={}},

      ]
      \begin{scope}[nodes={on chain, join=by arr}]

        \coordinate (in);
    \node (n4) [block] {$K_m = \num{2e-1}$\\ \unit{\newton\meter\per\volt}};

    \node (n5) [block] {$K_s = \num{5e-2}$ \\ \unit{\radian\per\newton\per\metre}};
    \coordinate (out);

  \end{scope}
  \node [below=1pt of n4] {Motor};
  \node [below=1pt of n5] {Spring};
  \node at ($(in)!.5!(n4.west)$) [label={above:$V$}, label={below:\unit{\volt}}] {};
  \node at ($(n4.east)!.5!(n5.west)$) [label={above:$T$}, label={below:\unit{\newton\meter}}] {};
  \node at ($(n5.east)!.5!(out)$) [label={above:$\theta$}, label={below:\unit{\radian}}] {};
\end{tikzpicture}

\end{center}
\end{document}

Could you let the arrow in the middle of line? because mine is at the end of the line but the one from the desired one is in the middle — kile, Jan 19 '23 at 11:59
@kile you should accept Zarko's answer as it solve this point! — NBur, Jan 19 '23 at 15:43

How to use tikz for sensor and actuator diagram

2 Answers2