Optimal fractional-order controller design using direct synthesis method


Yumuk E. , Güzelkaya M. , Eksin İ.

IET CONTROL THEORY AND APPLICATIONS, cilt.14, sa.18, ss.2960-2967, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 14 Konu: 18
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1049/iet-cta.2020.0596
  • Dergi Adı: IET CONTROL THEORY AND APPLICATIONS
  • Sayfa Sayıları: ss.2960-2967

Özet

In this study, an optimal fractional-order controller is proposed for a type of fractional-order model utilising the direct synthesis method. In that respect, the fractional counterpart of the second-order integer transfer function is selected as a closed-loop reference transfer function. The stability region of the fractional-order closed-loop reference transfer function is given via a theorem and related lemmas. Considering that a unity feedback loop is used, the parameters of the fractional-order closed-loop reference transfer function are specified based on the integral square error performance index within the specified stability region using a genetic algorithm. The time-domain characteristics of the optimal fractional-order closed-loop reference transfer function are compared with those of the optimal second-order integer closed-loop reference transfer function. The fractional- and integer-order controllers that are designed based on optimal closed-loop reference transfer functions are implemented on a real-time system. The performance of the fractional-order controller outperforms that of the integer counterpart on the integral square error criterion. Moreover, the simulation and practical results are consistent with each other.