Dissertation Defense: Modeling and Robust Stability of Advanced, Distributed Control Systems

Committee

• Dr. Rama Yedavalli, Chair
• Dr. David Hoelzle
• Dr. Vadim Utkin
• Dr. Junmin Wang

Abstract

Many control system applications are undergoing a transition from digital control to networked control. Networked control eases the process of utilizing information across geographic or other obstacles. This dissertation draws specific motivation from the aerospace industry, where both geographic and size considerations are important considerations. Networked control systems (NCSs) have unique considerations that require further research, including delay, uncertainty, and bandwidth constraints, addressed in this dissertation. First, modeling of delays are improved upon by presenting a compact formulation that accounts for multiple independent delays. Second, uncertainty is addressed from the continuous-time domain using robust stability and robust performance. To comprehensively address NCSs, several new theorems with a new extension allowing for time-varying systems, are presented for delay-free discrete-time systems and delay free, single lumped-delay, multiple delay (MD), and estimator compensated MD sampled-data systems. Third, bandwidth considerations are addressed by allowing for multiple sampling of sensors. In addition, advanced control techniques are addressed that take advantage of formulations presented in this dissertation. Namely, hierarchical control and a procedure for obtaining an optimized robust controller that accounts for MDs are discussed. Examples are shown throughout the dissertation based on a linear turbine engine model.