Stability analysis and intermittent control synthesis of a class of uncertain nonlinear systems.
In this paper we consider a linear system subject to norm bounded, bounded rate time-varying uncertainties. Necessary and sufficient conditions for quadratic stability and stabilizability of such class of uncertain systems are well known in the literature. Quadratic stability guarantees exponential stability in presence of arbitrary time-varying uncertainties; therefore it becomes a conservative approach when, as it is the case considered in this paper, the uncertainties are slowly-varying in time....
Si studia il problema della sintesi per un problema di controllo stocastico con equazione di stato lineare e funzione costo convessa.
The paper presents the technique of splitting operators, intended for perturbation analysis of control problems involving unitary matrices. Combined with the technique of Lyapunov majorants and the application of the Banach or Schauder fixed point principles, it allows to obtain rigorous non-local perturbation bounds for a set of sensitivity analysis problems. Among them are the reduction of linear systems into orthogonal canonical forms, the general feedback synthesis problem, and the pole assignment...
The tracking and regulation problem is considered for a class of generalized systems, in case of exponential reference signals and of disturbance functions. First, the notions of steady-state response and of blocking zero, which are classical for linear time-invariant systems, are given for generalized systems. Then, the tracking and regulation problem is stated and solved for the class of generalized systems under consideration, giving a general design procedure. As a corollary of the effectiveness...
For a block lower triangular contraction T, necessary and sufficient conditions are given in order that there exist block lower triangular contractions T_{1,1}, T_{2,1} and T_{2,2} such that T_{1,1} T U_T = [ ] T_{2,1} T_{2,2} is unitary. For the case when T^*_{1,1} and T_{2,2} have dense ranges, all such embeddings are described. Each unitary embedding of UT induces a contractive realization of T , and various properties of this realization are characterized in terms of the unitary embedding.