We propose a novel method called Soft-control, as a non-destructive way, to interven into the collective behavior of multi-agent systems..

Multi-agent methodology is used for a wide range of purposes, such as distributed intelligence, social groups, economics systems, biological and ecological modeling, etc.Usually there is no central controller, while agents interact locally.The system self-organizes and shows collective behavior which is a macroscopic phenomenon at a system level different from the bottom level.

An important and natural question is how to coordinate the collective behavior of the system if the system cannot be re-designed, especially, the interaction rule of the already-existing agents cannot be changed?

We proposed the idea of Soft-control, which is a nondestructive intervention to the collective behavior of multi-agent systems. By adding special agents (shills) into the system, we control the collective behavior by controlling the shills. In this way, the coordination avoids changing the interaction rules of already-existing agents in the system.

On the other hand, soft-control also provides a possible way for design of man-made MASs. By adding one/some ‘clever’ shills to coordinate the collective behavior will release us from the subtle design of interaction rules for many locally interacting agents.