\documentclass{standalone}
\usepackage{tikz}
\usepackage{siltex}
\usetikzlibrary {arrows.meta,positioning}
\tikzset{nodes={text height=.7em, text width=2.8cm, align=center,
draw=black!50, thick, font=\footnotesize, fill=white},
>={Stealth[round,sep]}, rounded corners, semithick}
% Compliant PDF
\usepackage[a-3u]{pdfx}

\begin{document}
\begin{tikzpicture}[y=0.8cm,x=3.2cm]
    \node (pp) {Path planning};
    \node (ip)[below=1 of pp]  {Interpolation};
    \node (ik)[below=1 of ip]  {Inverse Kinematics\\/Lookup Table};
    \node (sd)[below=1 of ik]  {Stepper driver};
    \begin{scope}[nodes={right, draw=none, fill=none, midway,text width={}}]
        \path[->] (pp) edge node {$x,y$} (ip)
              (ip) edge node {$x,y$} (ik)
              (ik) edge node {$\phi,\psi$} (sd);
    \end{scope}
\end{tikzpicture}
\end{document}
