Control Vector Selection with Delay Estimation in Wireless Networked Control Systems

In a sampled-data wireless networked control system, bursty packet losses and random delays could cause unstable behavior of controlled objects. In order to compensate these network-induced effects, we extend a packetized predictive control method, where multiple future control vectors are generated from estimated states of controlled objects and they are packed into a single packet transmitted over the wireless network. In the extended method, more control vectors are generated than in the conventional method, so that the controller should select appropriate control vectors among a set of those control vectors so as to be packed into a single packet. We thus consider a control vector selection scheme, where control vectors in each packet are selected based on the estimated average round-trip delays on the wireless network.