Stabilization and destabilization of fractional oscillators via a delayed feedback control

This paper discusses the problem of stabilization and destabilization of fractional oscillators by use of a delayed feedback control. A mathematical part of the problem consists in stability analysis of appropriate fractional delay differential equations with the derivative order varying between 1 and 2. Derived stability criteria are efficient and easy to apply when stabilizing or destabilizing fractional oscillators in the standard as well as inverted form. As a by-product of our results, we explicitly describe critical values of a delay control parameter when stability property turns into instability and vice versa. Evaluations of these stability switches are possible also in the limit harmonic case which brings new insights into classical stability results on this topic.(c) 2022 Elsevier B.V. All rights reserved.