Distributed optimisation and deconstruction of bridges by self-assembling robots

Multi-robot systems are often made of physically small robots, meaning obstacles that could be overcome by larger robots pose a greater challenge to them. This paper considers how a group of such robots could self-assemble into bridges to cross large gaps in their environment. We build on previous work demonstrating construction of cantilevers to show how they can be modified once the other side of the gap is reached. Two distributed algorithms are presented: one to reduce the number of agents in the initial structure once it is supported at both ends, and another to deconstruct this leaner structure when it is no longer required. A force-aware approach is taken to ensure that structures do not collapse under self-weight. The first algorithm is shown to be capable of reducing the number of agents in the structure to close to the optimum amount, whereas the second achieves safe and reliable deconstruction.