  This paper addresses the problem of navigation control of a general class of
uncertain nonlinear multi-agent systems in a bounded workspace of
$\mathbb{R}^n$ with static obstacles. In particular, we propose a decentralized
control protocol such that each agent reaches a predefined position at the
workspace, while using only local information based on a limited sensing
radius. The proposed scheme guarantees that the initially connected agents
remain always connected. In addition, by introducing certain distance
constraints, we guarantee inter-agent collision avoidance, as well as,
collision avoidance with the obstacles and the boundary of the workspace. The
proposed controllers employ a class of Decentralized Nonlinear Model Predictive
Controllers (DNMPC) under the presence of disturbances and uncertainties.
Finally, simulation results verify the validity of the proposed framework.
