Collision-Free Formation Control With Global Network Integrity Maintenance via Preserving Induced-Subgraph Connectivity

Network connectivity is a necessary prerequisite to realizing distributed formation control. However, it is challenging to maintain the global network connectivity of a formation with local information because the communications between topological agents may be disconnected as formation maneuvers due to the range-limited sensing capabilities of agents. In this article, we propose a novel connectivity-preserving formation strategy to address the challenge. The core idea is to decompose global connectivity constraint into the induced-subgraph-preserving problems of each agent. Different from the state-of-the-art methods, our strategy can acquire the local algebraic connectivity directly at the level of maximal cliques, instead of estimating the global algebraic connectivity by hundreds of iterations. Consequently, it yields more flexibility in formation maneuvers and requires lower computing costs. Moreover, we treat the entire formation as a single rigid body and employ a variant of the optimal reciprocal collision avoidance algorithm to optimize the overall movement of the formation so that agents can maintain the desired shape while avoiding obstacles. Here, the position and orientation of the desired formation are negotiated by the agents using only local peer-to-peer information. Simulation results verify that the proposed strategy can drive a group of agents to implement connectivity-preserving formations in obstacle-rich spaces.