Structural design and kinematic analysis of a welding robot for liquefied natural gas membrane tank automatic welding

Owing to the complex structures of welding materials, special conditions, and challenges during automatic liquefied natural gas (LNG) ship Mark III’s membrane tank, a series–parallel–series hybrid structure mobile robot having sufficient adaptability for corrugated plates in tanks was designed this study. The configuration had good workspace characteristics, it could always maintain certain distance angle between end torch weld line because its detection control system coordination. In study, degrees freedom, kinematic workspace, analyses were conducted mechanism. A simulation verification performed, ripple-trajectory-following experiment using real objects. experimental results showed that reasonable mechanism design, smooth motion, terminal control, thus meeting requirements tanks.