Controller design for uncertain systems under sampled measurements

This paper studies the problem of robust control of a class of uncertain nonlinear continuous-time systems with sampled measurements. The class of uncertain systems is described by a state-space model with unknown cone-bounded nonlinearity in the state equation and time-dependent norm-bounded parameter uncertainly in the state and out-put equations. Our attention is focused on the design of linear controllers using sampled output measurements. We address the problem of robust H∞ control in which both robust stability and a prescribed H∞ performance are required to be achieved irrespective of the uncertainties. The H∞ performance measure involves both continuous-time and discrete-time signals. It has been shown that the above problems can be recast into H∞ syntheses for related linear sampleted-data systems without parameter uncertainty and unknown non-linearity, which can be solved in terms of Riccati differential equations with finite discrete jumps. An examples is given to show the potential of the proposed technique.