Towards scalable autonomous underwater construction with free-floating robots

This thesis presents the first free-floating autonomous underwater construction system. Our system built structures weighing up to 100 Kg (75 Kg in water). Our robot builds structures made of standard cinder blocks and custom designed interlocking cement blocks. It is the first construction robot that uses active buoyancy compensation to efficiently transport building materials. It is also the first construction robot that can reconfigure visual fiducial markers on a foundation during the construction process to expand its working area.Underwater construction is a challenging problem for free-floating robots. Currents can buffet the robot, and visibility conditions can change. We focus on achieving underwater construction through a lens of co-design.We reframe the problem of underwater assembly by modifying the construction materials along with the morphology of the robot to make the task as easy as possible to achieve. We were able to achieve the construction of nontrivial structures with realistic materials using only a simple underwater robot which has no direct sensing of the state of the structure it builds.Mortarless assembly with high friction materials requires that components be designed with loose joints to prevent jamming. We develop a new kinematic analysis technique called PuzzleFlex which can compute the aggregate flexibility of systems of rigid modules with loose joints. We apply PuzzleFlex to optimize the shape of large interlocking cement blocks.Construction planning problems which would be intractable in a more general setting are possible when building passively aligning interlocking structures. We exploit this to develop the first planning algorithm for automatically deploying and reconfiguring localization infrastructure while building a structure at the same time. This work shows that we can use limited infrastructure to build interlocking structures at scale.