PID control design and implementation for laboratory scale infant incubator temperature using FOPDT model

Premature babies have difficulty for regulating their body temperature because weight deficiency. Infant incubator that equipped by temperature control system can support thermoregulation process in baby body. This paper explained design of temperature control system using Proportional-Integral-Derivative (PID) controller and its implementation to the laboratory scale infant incubator. The transfer function of infant incubator was obtained by step test method using First-Order and Dead Time (FOPDT) model where process gain K = 0.29, settling time Ts = 18s and dead time Td = 1. Ziegler-Nichols (ZN) and Direct Synthesis (DS) PID coefficients tuning method was used is this experiment and it resulted for ZN tunning method, proportional gain Kc = 20.14, integration time Ti = 0.2 and derivative time Td = 0.05 and DS tunning method proportional gain Kc = 5, integration time Ti = 18. PID controller was implemented to the Personal Computer (PC) with LabVIEW 2013 programing language, LabJack U3 HV data acquisition device and LM-35 temperature sensor. Set point of temperature that required was 350C with t and 250C initial temperature. The controller performance that resulted by this experiment were for ZN tunning method 38 minutes for settling time while DS tunning method resulted 12 minutes for setling time.