A nonlinear modelling approach to the sugar cane crushing process

Compaction of sugar cane varies all through the milling train due to the preparation methods and cane variety. Since compaction is the most crucial variable to influence torque loads and therefore sugar extraction, an adequate model for its estimation is needed. In this paper we put forward a nonlinear dynamical model based on a mass balance principle. The model utilizes the fact that the density of cane bagasse changes approximately linearly with the exerted pressure over it in the operation regions significant to torque control. The model is parametric in two variables which need to be tuned according to the properties of the cane. Our model gives promising results on real plant data and is expected to be useful in nonlinear control of sugar mills.