On connectivity preservation in mobile wireless multi-agent/node mesh networks

The paper considers the development of a mission planning system for a so-called `non-cooperative' multi-agent network. The network comprises two classes of agent: primary mission agents and relay agents. The primary mission agents have predefined tasks to execute and operate autonomously within the field of operation. Although these agents operate independently, from a mission planning perspective the base station is required to maintain contact. In order to ensure this, relay agents are employed under the direct command of the base station with the objective of maintaining connectivity. This paper proposes an architecture to control the relay agents in such a way that connectivity, as measured in terms of the Fiedler eigenvalue, is maximized subject to the cost of moving the relay agents. A model predictive control-like layer is used to generate a set of way-points to position the relay agents at specific places at specific instances of time to maximize connectivity. These way-points are then converted into continuous time paths for the relay agents to follow. A low level sliding mode controller implemented on each relay agent ensures that the proposed path is followed in a robust fashion.