Title: Indirect adaptive fuzzy control of non-linear systems using fuzzy supervisory term
Authors: Donia Ben Halima Abid; Mohamed Chtourou
Addresses: Electrical Engineering Department, National School of Engineers of Sfax, B.P: 3038, Sfax, Tunisia ' Electrical Engineering Department, National School of Engineers of Sfax, B.P: 3038, Sfax, Tunisia
Abstract: This paper focuses on the indirect adaptive fuzzy control of Single Input Single Output (SISO) non-linear systems with unknown linearities. The proposed adaptive fuzzy controller is based on feedback linearisation. Its parameters are updated online according to some adaptive laws such as tracking error-based method, composite tracking and modelling error-based approach as well as filtered composite tracking and modelling error-based approach. However, the approximation error introduced into feedback loop increases the difficulty to guarantee the stability of the closed-loop control system. To solve this problem a supervisory term should be added to the control law. In this paper, a fuzzy supervisory control is proposed to overcome the problem of chattering phenomena introduced by the classical supervisory term. Theoretical and simulation results prove the effectiveness of the proposed approaches. Faster and improved tracking is obtained by using second and third aforementioned adaptive laws combined with fuzzy supervisory control.
Keywords: adaptive fuzzy control; feedback linearisation; tracking error; composite adaptive law; filtered composite adaptive law; estimation error; supervisory controller.
International Journal of Computer Applications in Technology, 2019 Vol.59 No.2, pp.130 - 141
Received: 05 Mar 2018
Accepted: 04 May 2018
Published online: 27 Feb 2019 *