Soft Constrained based MPC for Robust Control of a Cement Grinding Circuit

In this paper, we develop a novel Model Predictive Controller (MPC) based on soft output constraints for regulation of a cement mill circuit. The MPC is first tested using cement mill simulation software and then on a real plant. The model for the MPC is obtained from step response experiments in the real plant. Based on the experimental step responses an approximate transfer function model for the system is identified. The performance of the MPC in the real plant compares favorably to the existing control system based on fuzzy logic. Compared to the other controllers, soft MPC handles the real time uncertainties effectively. It also regulates the cement mill circuits better and in a plant friendly way by using less variation in the manipulated variables (MVs).