Robotic construction of truss-like structures

Trussed structures are prevalent in everyday life. We use truss construction for the interior structural support of large buildings and in structures such as Eiffel Tower or power transmission towers as well as for temporary scaffolding to support workers and materials along the exterior. These structures are usually assembled on-site by human workers. However, there are many instances when construction of these structures is better suited for robots. These situations include environments with extreme temperature, high toxicity (e.g. nuclear or radiation accidents) or structurally unsafe areas (e.g. collapsed buildings). In these instances, more automated approaches are needed to build these structures.;This thesis will develop general methods for automated robotic construction. In order to test these approaches, we have created a robotic construction infrastructure at the GRASP Lab of the University of Pennsylvania. This system is comprised of several quadrotor helicopters with simple grippers, simple modular construction elements, and a motion capture system. With the limitation and constraints of this infrastructure in consideration, several algorithms for constructing truss-like cubic structures using these modular elements are developed. First, an algorithm, which can construct a class of cubic structures without holes, is described. This algorithm is extended to several new algorithms capable of closure of holes, which effectively expands the class of cubic structures to those that contain holes. Finally, these approaches are generalized for a larger class of lattice types including tetrahedral lattices. For each algorithm we provide analysis of experimental and simulated results as well as proofs of correctness and discussions of benefits and limitations.