Dynamic control of systems with variable state-delay

The problem of designing dynamic controllers for a class of linear dynamical systems with time-varying delays subject to input disturbance as well as output measurement error and in which some parameters are unknown-but-bounded is considered. It is establishing that when certain structural constraints are met, then two stabilizing controllers can be constructed to render the closed-loop system ‘globally practically stable’. The controllers have three terms: a growth term, an output-driven term and a nonlinear term. Robustness of the developed dynamic controllers against mismatched uncertainties is also proved. Simulation studies are carried out on a water-quality model to illustrate the potential of the control methodology.