Research On Optimal Control And Process Modeling For Coloured Coating Plate Production

The color coating steel plate is named as organic coating plate, too. The colored coating plate production is an important part of cold-rolled sheet steel strip production. Currently, colored coating plate production owns a lot of problems such as serious energy consumption, low efficiency, waste raw material in our country. The research on coating process modeling and optimum control problems aiming at reducing production costs, improving product quality, reducing defective, improving quality of goods has important theoretical and practical significance.This paper first introduces the color sheet production line process and the basic principle, describes the detail of the color sheet production line process, analyses the main influencing factors of the coating process. Through deeply study of the coating principle, this article analyses the important process parameters, such as the entrance oil film thickness, the roll radius and the surface tension of liquid coating. The paper treats the roll speed ratio, the gap thickness between the rolls and the applicator roll speed as operating variables. Then hydrodynamic lubrication theory and capillarity condition have been combined to establish the mechanism model of the thickness of coating on the basis of predecessors’achievement. Simulation results show the validity of the model. Then, the article utilizes the coating process model established above to simulate the actual process by generating data, establishes a prediction model based on data using kernel partial least-squares (KPLS) method. On these foundations above, the paper treats the operating variables as the decision variables, the max economic efficiency as the optimized objective, and gets the optimized results using the particle swarm optimization algorithm optimize to calculate. Due to the existence of uncertainty resulted by error of the prediction model, the paper try to use sequential quadratic programming(SQP) iterative optimization control method for colored coating plate production, combining the batch and utilizing actual production information to update the control input so as to continuously improve the indicators of the actual profit. The simulation shows its effectiveness.