Stability Criterion for a Single Decision-Making Node in Decentralized Material Handling Systems

Decentralized control concepts are today's answer to deal with growing decision networks and their increasing decision-making complexity. However, influencing the networks dynamics with a decentralized, and hence rather local view of the network, can cause undesirable effects such as: oscillatory network conditions, ruptures of network constraints and finally network breakdowns. In the first section of this paper an oscillation problem in decentralized material handling systems is presented, then a decision-making node with such an oscillatory problem is modeled and simulated. The decentralized control approach applied here is based on delayed feedback information with time-varying delays. Finally an analytical approach for determining the stability of such single network nodes, which was developed by Mehdi and Boukas (2003), is evaluated by comparing the result obtained from it with the results of the simulations.