Robotic Concrete 3D Printing Continuous Toolpath Planning: From Single Curve to Voxel-Based Systems for Design-to-Production of Urban Furnitures

This paper discusses the development of integrated design-to-production frameworks for Robotic Concrete 3D Printing (RC3DP) of context-specific urban furniture projects. The study focuses on two main objectives: developing computational methods for continuous toolpath planning of bespoke components and examining integrated frameworks to make design-to-production systems more socio-environmentally inclusive and tailored to specific contexts. Following an introduction to outline the key challenges of continuous robotic concrete 3D printing, the paper is organized into two sets of case studies. The first set explores curved-based continuous 3D printing for surface-based design strategies, and the second set investigates voxel-based approaches for volumetric design 3D printing. Curve-based projects consisted of three case studies. The first case uses an AI-enabled generative system to translate a porous, cellular structure to a continuous toolpath with variable heights. The second case study is based on a workflow using a controlled reaction-diffusion algorithm as a generative strategy to create continuous infill for complex geometries. The third project focuses on growing larger than the size of the production setup by testing the assembly of multiple printed components, all produced with continuous toolpaths. The workflows and projects are developed as an integral part of a graduate-level digital design and fabrication course focusing on inclusive automation and robotic concrete 3D printing. Therefore, in addition to sharing the details of the developed computational design to production methodologies, the paper discusses the research findings from pedagogical lenses. Building on these cases, the investigation advances to the development of a generative system centered on voxels, employing a tetrahedron structure. This volumetric approach simultaneously produces external surface tectonics and internal infill through a seamless toolpath. The paper concludes by presenting sets of guidelines and future directions for both the introduced curve and voxel-based approaches in Robotic Concrete 3D printing, emphasizing the early integration of computational and fabrication intelligence into the design process.