Multi-input Fuzzy Logic Controller for Brushless dc Motor Drives

Abstract

The brushless dc motors are used in various applications such as defence, industries,robotics, etc. In these applications, the motor should be precisely controlled to give the desiredperformance. The proposed controller systems consist of multi-input fuzzy (two-and three-input)logic controller (FLC) and multi-input integrated fuzzy logic controller (IFLC) for the speed controlof brushless dc servomotor drive. The input for the controllers are error e(k), change in error[first derivative of error ce(k)] and change of change in error [second derivative of error cce(k)]with a single-output. The error cce(k) is substantial at the overshoots/undershoots and is thereforeessential for accurate speed control of brushless dc motor. The error cce(k) has been introducedfor the first time in the literature as one of the input in the FLC and IFLC design. The IFLC isdesigned using FLC and proportional derivation integral (PID) controllers. The controller systemshave been studied systematically for the transient and steady-state conditions. The three-inputIFLC is found to be superior, more robust, faster, flexible, and is insensitive to the parametervariations as compared with the FLC (with two-and three-input) and conventional two-inputIFLC