Research Paper On Fuzzy Logic

Fuzzy logic is a logical system, which is an extension of multi valued logic. However, in a wider sense fuzzy logic (FL) is almost synonymous with the theory of fuzzy sets, a theory which relates to classes of objects with un sharp boundaries in which membership is a matter of degree. In this perspective, fuzzy logic in its narrow sense is a branch of FL. Fuzzy Logic Toolbox software. What might be added is that the basic concept underlying FL is that of a linguistic variable, that is, a variable whose values are words rather than numbers. Another basic concept in FL, which plays a central role in most of its applications, is that of a fuzzy if-then rule or, simply, fuzzy rule. Although rule-based systems have a long history of use in Artificial

5. The error ‘e’ and change in error ‘ce’ are the real world numerical variables of the system. The FLC consists of three stages: the fuzzification, rule execution, and de fuzzification. In the first stage the crisp variables e(k) and de(k) are converted into fuzzy variables E(k) and dE(k) using the triangular membership functions shown in Fig.

Based on this the elements of the rule table are obtained as shown in Table. 1, with ‘e’, ‘ce’ as inputs.
Table 1: Rule Base for fuzzy logic controller
CE→
E ↓ NB NM NS ZE PS PM PD
NB NB NB NB NB NM NS ZE
NM NB NB NB NM NS ZE PS
NS NB NB NM NS ZE PS PM
ZE NB NM NS ZE PS PM PB
PS NM NS ZE PS PM PB PB
PM NS ZE PS PM PB PB PB
PB ZE PS PM PB PB PB PB

PWM Switching Law
The switching device is the PWM converter. The switching signals are obtained as: if i_sl>V_sl. The upper switch of the i^th leg is ON and lower switch is OFF. Consequently if the upper switch of the i^th leg is OFF i_sl<〖i_sl〗^* the upper switch of the i^th leg is OFF and lower switch is