Naohisa Otsuka

Disturbance decoupling with quadratic stability for switched linear systems

In this paper, disturbance decoupling problems without stability and with quadratic stability for switched linear systems are formulated in the framework of the so-called geometric approach. Firstly, necessary and sufficient conditions for the problem without stability to be solvable are given. Secondly, sufficient conditions for the problem with quadratic stability to be solvable are given. Further, for switched linear systems composed of two subsystems necessary and sufficient conditions for the problem with quadratic stability to be solvable are also investigated. Finally, an illustrative example is shown.

Generalized invariant subspaces and parameter insensitive disturbance-rejection problems with static output feedback

In the geometric approach some generalized invariant subspaces for uncertain linear systems are investigated, and then various parameter insensitive disturbance-rejection problems with static output feedback are formulated and necessary and sufficient conditions for the problems to be solvable are presented. Further, some sufficient conditions which are useful to check the solvability conditions are presented using the notions of generalized invariant subspaces.

Generalized (C, A, B)-pairs and parameter insensitive disturbance-rejection problems with dynamic compensator

In the so-called geometric approach, the notion of the generalized (C, A, B)-pairs is introduced for uncertain linear systems, and its properties are investigated. Further, the parameter insensitive disturbance-rejection problem with dynamic compensator is formulated and some sufficient conditions for the problem to be solvable are presented.

The disturbance decoupling problem with stability for switching dynamical systems

Abstract The disturbance decoupling problem with stability is dealt with by means of the geometric approach for switching systems. The existence of feedbacks which decouple the disturbance and, at the same time, assure stability is difficult to characterize, since the action of the feedback couples with that of the switching law. Under suitable conditions, it is shown that the above requirement can be dealt with in separate ways and this allows us to state a checkable necessary condition and, on that basis, also a sufficient condition for solvability of the problem.

A note on robust disturbance-rejection problems for infinite-dimensional systems

In this paper, for infinite-dimensional systems characterized by unknown and unbounded system operators, some sufficient conditions for robust disturbance-rejection problems to be solvable are studied in the framework of the so-called geometric approach.

A necessary and sufficient condition for parameter insensitive disturbance-rejection problem with state feedback

In this paper a necessary and sufficient condition for a parameter insensitive disturbance-rejection problem with state feedback which was pointed out as an open problem by Bhattacharyya to be solvable is proved. A constructive algorithm of simultaneously (A,B)-invariant subspaces for a finite-number of linear systems and a relationship between simultaneously (A,B)-invariant subspaces and generalized (A,B)-invariant subspaces play an important role to prove the main result.

Robust disturbance-rejection problems for linear /spl omega/-periodic discrete-time systems

Two robust disturbance-rejection problems with state feedback and with incomplete-state feedback for linear /spl omega/-periodic discrete-time systems are studied in the framework of the so-called geometric approach. Also, some necessary conditions and/or sufficient conditions for the problems to be solvable are presented.

Block decoupling by incomplete state feedback for linear multivariable systems

Block decoupling and block triangular decoupling problems with incomplete state feedback are discussed for linear multivariable systems, and their solvability results are presented using the geometric approach of Wonham. Some illustrating examples are given.

Necessary and sufficient conditions for parameter insensitive disturbance-rejection problems with dynamic output feedback

In this paper, necessary and sufficient conditions for the parameter insensitive disturbance-rejection problem with dynamic output feedback which was studied in Otsuka(1999) to be solvable are given for the structured uncertain linear systems. Further, necessary and sufficient conditions for the solvability of the problems with static output feedback and state feedback are also studied as special cases. The obtained results contain some extensions of the previous results to the structured uncertain linear systems.

Decoupling by incomplete state feedback for infinite dimensional systems

The decoupling problem with incomplete state feedback for infinite dimensional linear systems is studied in the framework of geometric approach. Under certain assumptions, necessary and/or sufficient conditions for this problem to be solvable are presented.