  We present a system enabling a modular robot to autonomously build structures
in order to accomplish high-level tasks. Building structures allows the robot
to surmount large obstacles, expanding the set of tasks it can perform. This
addresses a common weakness of modular robot systems, which often struggle to
traverse large obstacles.
  This paper presents the hardware, perception, and planning tools that
comprise our system. An environment characterization algorithm identifies
features in the environment that can be augmented to create a path between two
disconnected regions of the environment. Specially-designed building blocks
enable the robot to create structures that can augment the environment to make
obstacles traversable. A high-level planner reasons about the task, robot
locomotion capabilities, and environment to decide if and where to augment the
environment in order to perform the desired task. We validate our system in
hardware experiments
