Title: Real-time optimisation study of the step size factor in MFAC based on the barrier function method

Authors: Fei Li; Shouli Gao; Li Zeng; Dongya Zhao

Addresses: College of New Energy, Chinese University of Petroleum (East China), Qingdao, 266580, China ' College of New Energy, Chinese University of Petroleum (East China), Qingdao, 266580, China ' College of New Energy, Chinese University of Petroleum (East China), Qingdao, 266580, China ' College of New Energy, Chinese University of Petroleum (East China), Qingdao, 266580, China

Abstract: The effectiveness of the model free adaptive control (MFAC) method relies heavily on the selection of the step size factor. The selection of inappropriate value of the step size factor can greatly reduce the effectiveness of the model free adaptive controller or even lead to the instability of the control system. In this paper, a real-time optimisation method is proposed for the step size factor in compact form dynamic linearisation based MFAC (CFDL-MFAC) scheme. Theoretical analysis reveals that it has higher convergence accuracy than the conventional CFDL-MFAC method, and finally the superiority of the method is further verified by simulation examples.

Keywords: MFAC; model free adaptive control; step size factor; real-time optimisation; convergence accuracy.

DOI: 10.1504/IJAAC.2025.147196

International Journal of Automation and Control, 2025 Vol.19 No.4, pp.395 - 411

Received: 05 Dec 2022
Accepted: 28 Feb 2024
Published online: 11 Jul 2025 *

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