  Reliance on external localization infrastructure and centralized coordination
are main limiting factors for formation flying of vehicles in large numbers and
in unprepared environments. While solutions using onboard localization address
the dependency on external infrastructure, the associated coordination
strategies typically lack collision avoidance and scalability. To address these
shortcomings, we present a unified pipeline with onboard localization and a
distributed, collision-free motion planning strategy that scales to a large
number of vehicles. Since distributed collision avoidance strategies are known
to result in gridlock, we also present a decentralized task assignment solution
to deconflict vehicles. We experimentally validate our pipeline in simulation
and hardware. The results show that our approach for solving the optimization
problem associated with motion planning gives solutions within seconds in cases
where general purpose solvers fail due to high complexity. In addition, our
lightweight assignment strategy leads to successful and quicker formation
convergence in 96-100% of all trials, whereas indefinite gridlocks occur
without it for 33-50% of trials. By enabling large-scale, deconflicted
coordination, this pipeline should help pave the way for anytime, anywhere
deployment of aerial swarms.
