Aggregation of heterogeneous units in a swarm of robotic agents

Formation of patterns in a system of interacting units of heterogeneous types is a self-organized behavior which is seen in many biological systems. Earlier research in this area has indicated that such pattern formation behaviors in biological cells and tissues are made possible because of difference in the adhesivity between different types of cells or tissues. Inspired by this differential adhesivity model, in our earlier research, we had presented a decentralized approach based on differential artificial potential to achieve the segregation behavior in a swarm of heterogeneous robotic agents in which agents of different types formed spatially separate clusters. In this paper, we extend that work by presenting an approach to achieve aggregation in which agents of different types get uniformly mixed with each other. The method is based on the proposition that agents of different types experience varying magnitude of potential while interacting with the agents of different types. An analysis of the system with the proposed approach in Lyapunov sense is carried out for stability. Extensive simulation studies and numerical analysis suggest that the proposed method would lead a population of heterogeneous agents to an aggregated configuration.