Conventional fuzzy control and its enhancement

TLDR

Conventional fuzzy control mainly consists of fuzzy two‑term and fuzzy three‑term control. This paper provides a systematic analysis and design for conventional fuzzy control. The authors propose a robust rule base for fuzzy two‑term control with scaling‑gain tuning, present a digital implementation to mitigate sampling effects, introduce a simplified fuzzy three‑term controller, and outline a two‑level tuning strategy linking proportional/integral/derivative gains to scaling gains and optionally adjusting control resolution. Simulations on various order models demonstrate the characteristics of fuzzy control, validate the new design methods, and show the enhanced fuzzy three‑term controller’s advantages.

Abstract

Conventional fuzzy control can be considered mainly composed of fuzzy two-term control and fuzzy three-term control. In this paper, more systematic analysis and design are given for the conventional fuzzy control. A general robust rule base is proposed for fuzzy two-term control, leaving the optimum tuning to the scaling gains, which greatly reduces the difficulties of design and tuning. The digital implementation of fuzzy control is also presented for avoiding the influence of the sampling time. Based on the results of previous fuzzy two-term controllers, a simplified fuzzy three-term controller is proposed to enhance performance. A two-level tuning strategy is also planned, which first tries to set up the relationship between fuzzy proportional/integral/derivative gain and scaling gains at the high level, and optionally tunes the control resolution at low level. Simulation of different order models show the characteristics of fuzzy control, effectiveness of the new design methodologies, and advantages of the enhanced fuzzy three-term control.