Advances in Automotive Production Technology – Digital Product Development and Manufacturing

Abstract

Combining conventional with additive manufacturing processes opens up new possibilities for the flexible, economical production of complex automotive components and structures with varying geometries. This hybrid manufacturing approach can be realized by 3D-Printing functional structures onto pre-existing parts and surfaces with Robotic Screw Extrusion Additive Manufacturing (RSEAM). The RSEAM process combines the dexterity of industrial robotic arms with the productivity and extensive material range of a screw extruder to provide a highly flexible additive manufacturing process. This paper addresses a critical challenge in hybrid manufacturing: creating suitable manufacturing programs for printing on irregular, non-planar surfaces, that deviate significantly from ideal CAD input. Deviations are classified as macro or micro based on their magnitude relative to the desired printing layer height threshold. We propose a slicing and path-planning algorithm that adapts ideal paths to scanned surfaces and generates optimized trajectories to handle both macro and micro deviations via distinct methods. Macro deviations are handled by offsetting the scanned surface to create layers, smoothing to remove micro deviations and morphing each layer from the ideal CAD onto them. Micro deviations are then accounted for in the first layer by calculating the local non-uniform layer height and locally adjusting the robot velocity. The resulting smooth robot trajectories ensure accurate local bead geometry and correct overall part geometry adaptation. The algorithm's output is validated and optimized within a digital twin of the manufacturing system to avoid collisions and singularities. The implemented algorithms are validated and demonstrated on a real-world automotive application.