OUTPUT-FEEDBACK CONTROL OF UNCERTAIN COUPLED SYSTEMS

The stabilization of uncertain dynamical systems on R(n) that admit a decomposition into two coupled subsystems of dimension n(c) and n(r) r espectively, is studied. We refer to the n(c)-dimensional sybsystem as the reduced-order system and to the n(r)-dimensional subsystem as the residual system: the overall n-dimensional system is termed the full system-the prototype for which is a mechanical model arising in the st udy of the active control of structures. Each subsystem is modelled by a differential equation with a linear nominal part and a nonlinear pe rturbation of a specified class. The output available for feedback pur poses is an R(nc)-valued linear combination of the state components of the full system and is subject to bounded measurement noise (with kno wn bound). An output feedback strategy is described and sufficient con ditions are obtained for the existence of a (calculable) global unifor m compact attractor (containing the state origin) for controlled syste ms of this class.