QA357 : Stability of periodic discrete-time linear systems by fractional-order derivative
Thesis > Central Library of Shahrood University > Mathematical Sciences > PhD > 2016
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Abstarct: In this thesis stability of fractional-order periodic discrete-time linear systems is explained. Fractional systems
provide an excellent instrument to describe memory and hereditary properties of various materials and
processes. The advantages or the real objects of the fractional-order systems are that we have more
degrees of freedom in the model and that a ‘memory’ is included in the model (fractional-order systems
have an unlimited memory).To modify the dynamic response of linear system we should change the poles
of state feedback matrices. Control of periodic fractional linear discrete-time system isn't possible in original form. But it can be changes to a periodic linear discrete-time with arbitrary delays in time and having practical stability conditions. Because of arbitrarily of delays we can make the conditions similar to fractional system that provides an excellent instrument to describe memory and hereditary properties of processes. We proposed a special
form of state feedback matrix to assign suitable eigenvalues to closed-loop monodromy matrix of system. But it makes large monodromy matrix and changing all of
eigenvalues make some problems. Reassigning a part of bad spectrums, leaving the rest of the spectrums
invariant, we have lower ordered matrix to modify the dynamic response of linear system and we can
make non-linear parametric for this new lower-ordered matrix by less expenses and better stability conditions. stabilization of fractional-order periodic discrete-time linear system by a complete non-
linear parametric approach for pole assignment with respect to stability and reachablity of system via
state feedback is proposed. Non-linear parametric feedback matrix make some freedoms in conditions
such as minimum norm of feedback matrix. Numerical examples illustrate the effectiveness of the proposed approaches.
Keywords:
#control #discrete-time # fractional derivative #linear #periodic systems #pole assignment #stability
Keeping place: Central Library of Shahrood University
Visitor:
Keeping place: Central Library of Shahrood University
Visitor: