On the External Stability of Linear Systems with Actuator Saturation Constraints, and the Decentralized Control of Communicating-Agent Networks with Security Constraints By

by Zheng Wen, M.S. Washington State University August 2007 Co-Chairs: Ali Saberi and Sandip Roy This thesis is motivated by the need to better understand the analysis and control of linear systems subject to constraints. We contribute to this field by pursuing research on two specific topics: 1) the external stability of linear systems subject to actuator saturation, and 2) the security of Communicating-Agent Networks (CANs). For the first topic, we study the disturbance responses of some canonical systems as the step toward better understanding of external stability of nonlinear systems. Specifically, for a saturating feedback-controlled double integrator, we delineate classes of (deterministic) disturbances that do and do not drive the state unbounded; further, for a saturating feedback-controlled single integrator driven by white noise, we fully characterize the evolution of the state’s probability distribution. For the second topic, we motivate and formulate concepts of security in the context of CANs, and present some preliminary results for two classical CANs: the Single-Integrator Network and the Double-Integrator Network.