Networked control systems with packet delays and losses

— We investigate the effect of packet delays and packet drops on networked control systems. First we consider the problem of where to locate a controller or state estimator in a network, and show that under a Long Packets Assumption (LPA) it is optimal to collocate it with the actuator. We then show that under the LPA, stabilizability is only determined by the packet drop probability and not the packet delay probabilities. We also consider a suboptimal state estimator without the LPA, based on inverting submatrices of the observability Krylov sequence. I. I Contention for the medium, channel fading, and interference in networks, lead to packet delays and losses. Even though observations may be taken at regular instants, their arrivals after passage through the network may be random since collision detection and avoidance algorithms use random backoffs and delays, or they may even be dropped due to the losses in the wireless medium or collisions. Hen...

• Type: Conference
• Year: 2008
• Where: CDC
• Authors: Craig L. Robinson, P. R. Kumar
• Keywords: CDC 2008, Control Systems, Long Packets, Packet Delays, Packet Drops