Adaptive robotic tamping: a novel robotic method for formative surface finishing in earth-based additive manufacturing

Abstract Earth-based materials are emerging in additive manufacturing (AM) for construction due to their wide availability and minimal environmental impact. However, the inherent rough surface texture from AM processes poses significant barriers to getting accepted by the building industry partly due to its tendency to accumulate dust, dirt, and pollutants, leading to challenges in long-term maintenance. To address this challenge, this paper presents a novel ’tamping’ technique as a formative robotic surface finishing method to achieve smooth surface quality in structures produced through robotic additive manufacturing with earth-based materials, particularly for the Impact Printing process, which involves the discrete aggregation of workable parts at high velocity to create volumetric structures. The tamping process achieves a smooth surface finish by iteratively compacting the structure’s surface while the material remains workable, leveraging the extended workability period of the material post-deposition and eliminating the need for additional materials for surface finishing. This paper describes the experimental setup consisting of a custom end-effector and electronic integration for adaptive control and presents preliminary results of the robotic tamping process, demonstrating its potential to improve surface quality and affirming the viability of the Impact Printing method for sustainable construction practices within the industry.