SIGRADI 2015 746 Introduction The introduction of digital tools and associative modeling into design in the last few decades allowed architects and designers to create complex geometries relatively easily. Yet, when realizing these complex structures in the ‘real world’, that easiness fades away, the process becomes tedious and ad-hoc, and often demands some painful compromises in the inal outcome. In this paper we propose to rethink the design- construction worklow by providing geometric information of the design model for an on-site robotic arm that performs the assembly process. The robotic arm is then an integrated part of the design process from its early stages, which in turn accounts for a more continuous and smooth design- construction worklow. In many industries, and for many years now, industrial robots have been crucial components in complex assembly lines (e.g. the car industry) (Carlsson, 1989). As the ability of the designer to easily generate complex structures increases, the demand for an analogous assembly technology in the building industry is evident. The gap between cutting-edge digital design methods and current on-site construction methods is quite substantial, as the greater part of the building industry still uses standard tools. The automation of the assembly process will decrease the gap between design and construction processes, and between the initial architectural model and the inal outcome. In recent years we have seen multiple projects that tackle the issue of robotic assembly in architecture. The majority of them involve vertical brick stacking, where a minor change in the orientation of each brick allows the creation of non-standard structures (Figure 1). This strategy, though impressive and novel, imposes a great number of constrains on the geometry and on the inal outcome. We propose an alternative method for assembly that enables the construction of double curved self-supporting structures. (For the purpose of this paper, we will call these structures ‘complex structures’ from now on.) On-site Robotic Assembly of Double-curved Self-supporting Structures Abstract Robotic assembly of architectural structures has been an area of research for a few decades. Yet, current methods impose a large number of constraints on the geometry of those structures. In this paper we introduce a method for robotic assembly that enables the construction of double curved self-supporting structures. Latest research challenges have focused on the assembly of sophisticated brick structures and on sensor feedback systems for handling accuracy. We propose an alternative strategy to tackle tolerance handling in complex structures that rely on geometry. The intelligence of the system lies in two main aspects: a subdivision technique that incorporates the robot’s constraints as well as the structural equilibrium of the structure during each step of assembly, in order to omit the use of scaffolding; and a match between geometric information and the robot’s movements in a robot programming environment. As a proof of concept, we fabricated a portion of a full-scale double-curved structure. The structure was assembled without scaffolding by a portable KUKA KR10 on a randomly picked site. This project aims to demonstrate an easy and simple method for robotic assembly that enables the realization of digitally generated complex geometries as concrete complex structures. Keywords: Robotic Assembly, Self-supporting Structure, On-site Assembly, Double Curvature, Construction Tolerances Inés Ariza MIT, USA iariza@mit.edu Merav Gazit MIT, USA mgazit@mit.edu