Robots Building Bridges, Not Walls

Abstract

The TERMES system is a robot collective capable of constructing 2.5D user-specified structures with specialized bricks. This work extends the original system, by enabling 3D construction without added complexity in the robots. To do this, we introduce an expandable brick which complies with the original TERMES hardware and is inexpensive and fast to fabricate. We further show a decentralized algorithm that permits an arbitrary number of robots to use both original and expandable bricks to build structures with overhangs over convex cavities, i.e. with bridges and roofs. Finally, we discuss a mechanical redesign of the robots towards decreased system cost, fabrication and maintenance time. Although more work is needed to realize construction of large-scale overhangs in practice, our work represents an important step towards construction of complex structures by minimalistic and scalable robot collectives.