The design of decentralized robust tracking controllers for large-scale uncertain systems with time-delay (Q2783696)

The authors present sufficient conditions for decentralized robust tracking of an uncertain large-scale system with time delay. The conditions have the form of linear matrix inequalities and the design problem is formulated as a convex optimization problem with linear constraints. The uncertainties in system and control matrices are supposed to be structured and value bounded and the state equations are disturbed by an unknown but constant signal. The design objective is to find a decentralized state feedback law which guarantees that the output of each subsystem approaches its reference signal asymptotically in spite of system uncertainties and constant disturbances. The line of reasoning is based on the Lyapunov type machinery applied to the augmented model of the system which contains both the model of the uncertain subsystem and an output of an integration part of the local controller. Its use leads to solvability of linear matrix inequalities which constitute a sufficient condition of successful design. To obtain feedback gain as small as possible, a convex optimization problem is formulated. No example is given.