Multi-hopping induced gain scheduling for wireless networked controlled systems

Abstract

A multi-hopping induced gain scheduler for Wireless Networked Controlled Systems (WiNCS) is proposed. The control scheme is based on a client. serv er architecture. The data packets are assumed to be carried over a network composed of wireless sensor nodes running the 802.11b protocol. The number of hops necessary for packets to reach their destinations is variable and depends on current traffic conditions. Changes in the number of hops induces changes in the latency times introduced by the communication network in the feedback loop. To deal with these changes an LQR. output feedb ackscheme is introduced, whose param eters are adjusted according to the num b er of the hops. The weights of the LQR controllers are sub seq uently tuned using LMIs to ensure a prescribedstab ility m argin despite the variable latency times. The overall scheme resembles a gain scheduled controller with the number of hops play ing the role of the scheduling parameter. Simulation results on the NS-2 simulator are provided to highlight the efficacy of the proposed scheme.