Plant control over QoS-enabled packet networks

Performance and stability in networked control systems are strongly affected by transmission delays and packet dropouts. We propose a control architecture based on the Differentiated Services technique to guarantee quality of service on the network. The crucial observation is that not all signalstraveling on the network have the same importance. An adaptive packet-marking strategy has been developed to choose at run-time the transmission priority according to the importance of the data and the current network condition. System/network co-simulation applied to a bottleneck scenario validates the proposed approach and shows that better performance can bereached without increasing the bandwidth if network resources are used in a smarter way.