Improved Performance of Heat Exchanger using Multi-Variable Quantitative Feedback Theory based Controller

This paper deals with a pre-compensated diagonal quantitative feedback theory (QFT) based controller for a multivariable uncertain plant. A 2×2 heat exchanger having linearised dynamics along with interval type of parametric uncertainty is considered as the plant. The controlled plant is required to meet a certain stability, sensitivity and robust tracking specifications. First pre-compensators are designed to make the plant a diagonally dominant one. Then, diagonal controllers are designed to make the pre-compensated plant meet the stability and sensitivity specifications using QFT. Lastly the pre-filters are designed to ensure the robust tracking requirement. The effectiveness of the proposed controller is tested through numerical simulation. The results reveal that the proposed controllers successfully control the plant with minimum coupling and interaction. The comparative study reveals that the proposed controllers outperforms some of the existing controllers in literature.