Control Difuso Adaptable

d©2010 International Journal of Computer Applications (0975 - 8887) Volume 1 – No. 27

Design and Implementation of Adaptive Fuzzy Controller for Speed Control of Brushless DC Motors
N.Senthil Kumar
Professor, EEE Department Mepco schlenk Engineering College, Sivakasi, Tamilnadu India

C.Senthil Kumar
Assistant Professor, EEE Department, PSR Engineering College, Sivakasi Tamilnadu, IndiaABSTRACT
This paper presents the design and implementation of an adaptive fuzzy logic controller for the speed control of brushless dc motors. The proposed system uses an adaptation of the slope of the membership functions of the variables used in the conventional fuzzy controller based on the magnitude of the error. A simulation analysis of the fuzzy controller and the adaptive fuzzycontroller are done and their performances are compared. Simulation results of both fuzzy and adaptive fuzzy controllers are presented. The adaptive fuzzy controller is better than the fuzzy controller based on the performance parameters considered. An experimental implementation of the designed adaptive fuzzy controller on an embedded microcontroller is also presented.

model [5, 6]. The fuzzy logiccontroller uses fuzzy logic as a design methodology, which can be applied in developing nonlinear system for embedded control. Simplicity and less intensive mathematical design requirements are the most important features of the FLC. Fuzzy logic control is derived from fuzzy set theory introduced by Zadeh in 1965. In fuzzy set theory, the transition between membership and non-membership can begradual. Therefore, boundaries of fuzzy sets can be vague and ambiguous, making it useful for approximate systems. Fuzzy Logic controller is an attractive choice when precise mathematical formulations are not possible [7, 8].

Keywords
Brushless DC motor, Fuzzy controller, Adaptive fuzzy controller, microcontroller.

PROPOSED SYSTEM

INTRODUCTION
Recently , permanent magnet brushless dc motor(PMBLDC) is very popular because of its attractive features such as high starting torque, high efficiency, low maintenance cost, absence of mechanical commutator, high speed operation, low volume to torque ratio, elimination of sparking and electromagnetic disturbances, noise. A PMBLDC motor is inside out construction of DC motor. The efficiency is likely to be higher than DC motor of equal size andthe absence of commutator and brushes, reduces the motor length. Hence the lateral stiffness of the motor is increased, allowing for high speeds [1, 2]. The power electronic converters required in brushless dc motor are similar in topology to the PWM inverter used in induction motor drives. Nowadays brushless dc motors are used in various applications such as defense, industries, robotics, etc.In these applications, motor should be precisely controlled so as to give desired performance. The classical controller need accurate mathematical model of the system and can perform well only under linear condition. Since the PMBLDC motor is highly coupled non-linear multivariable system, it is difficult to obtain its accurate mathematical model. Hence there is a need for intelligent controller.So an attempt is made to develop fuzzy controller for PMBLDC motor. The fuzzy logic controller (FLC) is indeed capable of providing the high accuracy required by high performance drive system without the need of mathematical model [3, 4]. FLC accommodates non-linearity without utilization of mathematical

Figure 1. Proposed system. Figure 1 shows the block diagram of proposed system. The systemabove is composed of brushless dc motor, six step inverter, gate drive for inverter, fuzzy controller and switching logic. Due to the presence of parameter variation and load disturbance in a BLDC motor, closed loop control is necessary, to obtain a desirable behavior. BLDC motor has three phase windings on stator and Permanent Magnet on rotor. In order to define the shaft position, rotor...