Throughout history, human progress has been defined by the mastery of materials, transitioning from stone and bronze to the steel age. However, this progression has not only been defined by the materials utilized but has also encompassed a shift in processes, moving from the industrial to the information era. Despite the advances in fabrication techniques, building large and detailed structures continues to pose an unresolved challenge. Cost, speed, performance and size are often mutually exclusive objectives that are bound by the materials and processes used.
In the search for new processes and materials, we can find inspiration in the oldest of all fabricators; life. In natural systems, a small set of 20 amino acids are assembled by ribosomes into coherent organisms with complex sensing, actuation and information storage. Nature represents the highest dynamic range assembly system known to mankind. But a question arises: can these benefits be extended to engineering systems at meso and macro scales?
The advantages of natural fabrication emanate from the use of digital materials and self-replicating assemblers. Digital materials are composed of precise and discrete building blocks like amino acids at the micro-scale or Lego building blocks at the meso scale. They are tolerant to noise, possess embedded metrology and their assembly can be highly parallelized. Lego structures can be built more repeatably than what a standard 3D printer can print despite the imprecise nature of human assemblers. This is because the metrology and the code for construction are embedded within the material itself.
In this thesis, a complete end-to-end autonomous digital material assembly system, that bridges the gap between a 3D model and a built structure with a flexible, comprehensive, and easy-to-use toolset is presented. All elements in the triad of autonomous digital assembly were developed, from the digital material to the robot and the controlling software. A digital material made of discrete 3D-printed octahedra lattices that can be magnetically or mechanically joined is utilized. Straight, curved and elongated lattices enable unparalleled geometric freedom.
This material can be picked up, transported and placed by a robotic assembler in the form of a 5DOF (degrees of freedom) cable-driven differential joint inchworm robot.
Most importantly, a flexible control platform capable of interpreting 3D models, developing the necessary robot movements for optimal construction and wirelessly controlling assembler robots powers the build process. This platform introduces some major innovations within the field. For starters, it is not limited to blocky grid domains as it is powered by inverse kinematics. It is also architected to enable cooperation between different assembler types by utilizing a work package system and presents wide abstraction layers allowing further development at higher levels with ease. Additionally, it provides a seamless control interface.