Robotic Automation of Adhesive Application in the Assembly of Lightweight Sandwich Structures

Abstract

Reducing the weight of vehicles while maintaining structural integrity is an important step toward achieving energy efficiency and sustainability. At the German Aerospace Center (DLR), lightweight sandwich panels, consisting of two thin aluminum sheets bonded to a lightweight core, are used in the construction of lightweight vehicles. These panels feature interlocking slots that allow them to be assembled into more complex structural forms. Finally, aluminum angle profiles are glued along the intersections of these panels. These profiles not only reinforce the joints but also lock the panels in place, completing the assembly process. At present, both the panel production and subsequent assembly are performed manually, resulting in process inefficiencies, inconsistencies, and high labour demands. This thesis builds upon the ongoing research at DLR aimed at automating the production and assembly of sandwich panels. The scope of the thesis is to develop an automated process for gluing aluminum angle profiles during panel assembly. This includes the design and implementation of a custom gripper for handling the profiles, as well as the development of a dispensing station that prepares the profiles for bonding. The interlocked structure is placed on a previously designed rotating platform, which will be assembled and modified as needed to suit the requirements of this system. A robotic manipulator uses the gripper to pick up the aluminum profiles, move them under the dispensing station to apply fast-adhesive stickers and glue, and subsequently adhere them along the joint edges of the panels. To ensure stability during the gluing process, custom brackets will be applied at the panel joints. All mechanical components will be modelled using Fusion 360, while the robotic operations will be programmed using RoboDK and PolyScope. The work will begin with an analysis of the current manual process, identifying key challenges and requirements. A review of existing methods in robotic adhesive application will inform the design. The broader goal is to improve process repeatability and precision, reduce manual effort, and contribute to the development of automated lightweight structure assembly processes