Managing Emergent Behavior in Distributed Control Systems

Abstract

Abstract : Distributed control architectures are becoming increasingly popular because their modularity makes them easy to install, configure, and modify. These benefits do not come for free. A population of asynchronously executing processes without central top-down control can exhibit unexpected or emergent behavior at the system level. To the plant engineer, this behavior may look lIke noise or error conditions, but it is generated by deterministic interactions among control elements, not random events or unit malfunctions, and it must be managed accordingly. Drawing on experiences in the Auto Body Consortium's Intelligent Resistance Welding project, we illustrate the potential for this kind of behavior among welding robots in an automotive body shop and in other applications, show how recent research in nonlinear systems theory and agent-based control can be used to detect and manage such interactions, and identify some requirements that these agent techniques place on emerging standards for data and control models.