LQR Control Design of Discrete-Time Networked Cascade Control Systems With Time Delay

Abstract

Series cascade control systems, in which, the output of one process drives a second process are studied extensively in literature. Traditional control design methods based on transfer function approach are used for design of cascade control systems with disturbances in inner loop and time delays in outer loop process. Design of current turboshaft engine control systems are based on cascade control system framework. Next generation aircraft engine control systems are based on distributed architecture, in which, communication constraints like time delays can degrade control system performance. Stability of networked cascade control systems for turboshaft engines in a state space framework is analyzed in the presence of time delays. Two architectures of networked cascade control systems are presented. Stability conditions for discrete-time cascade control systems are presented for each of the architecture with time delays which are more than the sampling time.