“…Previous work put an emphasis on the recognition of such elements [6], [9], [12], [14], [17]. Based on that work we focus on Dennis Nienhüser, Thomas Gumpp and J. Marius Zöllner are with FZI Forschungszentrum Informatik, Intelligent Systems and Production Engineering, Haid-und-Neu-Straße 10-14, 76131 Karlsruhe, Germany.…”