  We study robot construction problems where multiple autonomous robots
rearrange stacks of prefabricated blocks to build stable structures. These
problems are challenging due to ramifications of actions, true concurrency, and
requirements of supportedness of blocks by other blocks and stability of the
structure at all times. We propose a formal hybrid planning framework to solve
a wide range of robot construction problems, based on Answer Set Programming.
This framework not only decides for a stable final configuration of the
structure, but also computes the order of manipulation tasks for multiple
autonomous robots to build the structure from an initial configuration, while
simultaneously ensuring the stability, supportedness and other desired
properties of the partial construction at each step of the plan. We prove the
soundness and completeness of our formal method with respect to these
properties. We introduce a set of challenging robot construction benchmark
instances, including bridge building and stack overhanging scenarios, discuss
the usefulness of our framework over these instances, and demonstrate the
applicability of our method using a bimanual Baxter robot.
