Model predictive control over delay-based differentiated services control networks

Networked control systems are a well-known sub-set of cyber-physical systems in which the plant is controlled by sending commands through a digital packet-based network. Current control networks provide advanced channel access mechanisms to guarantee low delay on a limited fraction of packets (low-delay class) while the other packets (un-protected class) experience a higher delay which increases with channel utilization. We investigate the extension of model predictive control to choose both the command value and its assignment to one of the two classes according to the predicted state of the plant and the knowledge of network condition. Experimental results show that more commands are assigned to the low-delay class when either the tracking error is high or the network condition is bad.