Model Predictive Control of Important Parameters in a Paper Machine Headbox.

The modern headbox has many attributes that are highly significant for all paper-makers. Uniformity of flow, absence of streaks and large eddies, headbox stability and ease of operation are required features for all paper grades. Consistency in a headbox is a very important parameter in paper mills in their various stages of operations. Without the knowledge of consistency, it is not possible to optimize productivity with optimal quality. In the present study, a multivariable, linearized, state space model of a paper machine headbox was selected for control of consistency and liquid level in the headbox of a paper machine using the advanced control strategy Model Predictive Control (MPC). MPC uses a model to predict the process output along a future time horizon. It performs the calculation of a control sequence to optimize a performance index. It is based on receding horizon strategy so that at each instant the horizon is moved towards the future, involving the application of the first control signal of the sequence, calculated at each step. [ABSTRACT FROM AUTHOR]