طراحی یک کنترل کننده منطقی فازی نزدیک بهینه و گسترده

The paper describes a novel method for the design of a fuzzy logic controller with near-optimal performance in the wide range of operating conditions. The approach is based on the analysis of the system behaviour in the error state-space. The final control structure, in a form of a dual fuzzy logic controller, is arrived at in two stages. The first stage encompasses design and tuning of the PI-like fuzzy controller. The second stage consists of placing an additional fuzzy controller, of a structure similar to that of the first one, in parallel with the PI-like fuzzy controller designed in the first stage. The final structure of the dual fuzzy controller is obtained by synthesis and tuning of those segments of the second controller that are different. The resulting dual controller is characterised with high performance in the wide range of operating conditions, and with small number of parameters that can be adjusted using simple optimisation methods. The controller is developed and tested for a plant comprising a variable-speed DC motor drive.