Comparison Between Fuzzy Logic and PID Controllers in Temperature Control of Laboratory Incubator

Abstract

Incubators are very essential equipment that finds wide application in the fields of medical Laboratory and microbiological research organization. This is because Incubator monitors and maintains conducive environment that is suitable for culturing, or growing of micro bacterial and enzymes, for the purpose of clinical diagnoses in Health centres, or process development in manufacturing industries. In this paper, a transfer function model for an incubator was developed upon which a designed Fuzzy logic controller acts to control the incubator Temperature, by computing appropriate Voltage. A PID (Proportional Integral Derivative) controller was also designed and tested on the same model. Findings were that the fuzzy logic controller tracked the optimum Temperatures for culturing of Mesophilic and thermophilic bacterial at 37 0C and 54.94 0C respectively. In comparison with the Fuzzy logic controller, the PID controller tracked at 37 0C and 55 0C for the two selected set points. In addition, the fuzzy logic controller gave faster rise time ( 3.30 mS, 3.45 mS and 13.72 mS) and settling time ( 1.60 mS, 2.04 mS and 5.55 mS ) as compared to PID controller which presented longer rise time (53.61 mS, 53.68 mS and 53.62) and settling time ( 254 mS, 336 mS and 345 mS) for the given set points respectively.