Comparative study of the performance of fuzzy and conventional controllers applied in a bioprocess / Estudo comparativo do desempenho de controladores fuzzy e convencional aplicados em um bioprocesso

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The use of fuzzy controllers in bioprocesses has increased greatly in the last few years. In conventional controllers, assumptions and simplifications are often made to build a precise mathematical model that may be far from the real situation. In contrast, fuzzy controllers are an attractive technique for the control of plants that are ill-defined or non-linear systems. The high commercial value of the bromelain and its increasing demand in pharmaceutical and industrial applications justify the necessity of control to provide adequate operational conditions. Temperature control is crucial to avoid the irreversible protein denaturation and consequently to improve the precipitation yield. This work focus on the development of a comparative study between conventional and fuzzy controllers applied to a bromelain recover process from pineapple juice through the precipitation process with a1cohol at a low temperature, using Fieldbus network architeture. The Ziegler Nichols method was used to tuning conventional controllers. The parameters K: = 35 %/oC, ti = 28 s e td = 7 s was used to PID controller and K: = 35 %/oC e td = 31 s was used to PI controller. To tuning the fuzzy controller was tested different uni verse of discourse, base of rules and support sets of membership functions. The experimental results show the effectiveness of fuzzy controller in comparison with the conventional controllers. The fuzzy-PI controller presented reduced error parameter (ITr ), saved electrical energy (58 % smaller) and better recovery ofthe enzymatic activity (80 %)

ASSUNTO(S)

fieldbus logica difusa automação controladores pid bromelain fuzzy controller pid controller bromelina

ACESSO AO ARTIGO

Documentos Relacionados