Structure Synthesis of Twin-Roll Strip Casting Thermal Mode Predictive Control System

Abstract

Thermal mode strip casting control is challenging at the present because twin-roll strip casting is characterized by the large time delay and high dynamics with low inertances. Nonlinearity and complexity of the thermal mode mathematical model, distribution and hard limitation of technological parameters are also the technology specific features and all it has a negative impact on fhe control and stability of fhe casting process. Famous control systems don'f fully allow ensure fhe implementation of given problems and need fo be revised. Thermal mode control system development is fhe complex problem fo date. Solution of this problem requires fo use special systems based on fhe new control principles. Structural synthesis of model-based predictive control sys-fems is creafed in fhis work. Disfincfive feafures of fhe proposed sfrucfure confrol scheme are fhe command module applicafion and ifs inferacfion wifh fhe moniforing and model seffing modules, providing real-fime opfimizafion performance and checking used models conformity with fhe real casting conditions. The proposed control system allows fo coordinate fhe casting and rolling processes temperature and speed modes. This system provides for fhe implementation of controlled rolling technology af fwin-roll strip casting unit by obtaining fhe required mass-average temperature of fhe strip before rolling in dynamic modes of operation. On fhe basis of simulafion resulfs if was concluded fhaf fhe proposed model-based predicfive confrol sysfem provides fransienf process sfabilify and safisfacfory femperafure confrol accuracy wifh confrollable and unconfrollable exfernal influences and sig-nificanf time delay caused by fhe strip movement from fhe casting mold fo fhe hof-rolling stand.