  When a group of heterogeneous node dynamics are diffusively coupled with a
high coupling gain, the group exhibits a collective emergent behavior which is
governed by a simple algebraic average of the node dynamics called the blended
dynamics. This finding has been utilized for designing heterogeneous
multi-agent systems by building the desired blended dynamics first and then
splitting it into the node dynamics. However, to compute the magnitude of the
coupling gain, each agent needs to know global information such as the number
of participating nodes, the graph structure, and so on, which prevents a fully
decentralized design of the node dynamics in conjunction with the coupling
laws. To resolve this issue, the idea of funnel control, which is a method for
adaptive gain selection, can be exploited for a node-wise coupling, but the
price to pay is that the collective emergent behavior is no longer governed by
a simple average of the node dynamics. Our analysis reveals that this drawback
can be avoided by an edge-wise design premise, which is the idea that we
present in this paper. After all, we gain benefits such as a fully
decentralized design without global information, collective emergent behavior
being governed by the blended dynamics, and the plug-and-play operation based
on edge-wise handshaking between two nodes.
