On Some Predictive and Adaptive Fuzzy Controllers Based on Ensuring the Maximum Phase Reserve

Abstract The authors have already proposed a new method for the algorithmic design of the controller as part of an automatic control system (briefly, ACS). The method has the specific feature in ensuring the maximum phase reserve in the linear case, and it is immediately applicable to the field of electrical driving systems. The types of conventional controller (regulator, R) transfer functions (t.f.s) (H(s)) result as function of the types of controlled plant (CP) transfer functions (H(s)); only the cases of PI and PID controllers are taken into consideration in the paper. Several predictive and adaptive fuzzy controllers (FCs) are developed on the basis of the conventional PI and PID controllers; the design of these FCs is also presented. The proposed FCs ensure ACS performance enhancement that is pointed out by digital simulation for a case study; a comparative study of digital simulation results for ACSs with different types of controllers (conventional and fuzzy) is part of the paper. The FC is designed beginning from the linear controller (of PI or PID type) for the maximum phase reserve because the FC can be approximated as a linear element, and its parameters depend on the operating point. So, the term ”maximum phase reserve” from the title referring only to linear systems is justified.