PI multivariable control applied to temperature and humidity neonate incubators

This paper proposes multivariable PI control strategies for humidity and temperature of neonate incubator loop This process is a TITO system (Two Input Two Output). The transfer function matrix was identified using closed loop step response through sequential method that decouples the TITO system into four independent loops. Models of three parameters were used for the system loops due to simplicity. Two methods of PI tuning were then developed for the loops of the incubator with the main objective of ensuring robustness and stability, namely: i) design of decentralized PI controller using the modified Ziegler-Nichols method and ii) BLT method (Biggest Log-Module Tuning) revised. Extensive experimental test were performed and some results are presented in the paper.