Optimization Model For Roll Speed Control Of Twin-roll Thin Strip Continuous Casting

In order to solve the problem that the thin strip is low-yield, cracked, broken easilyand mid-seizing in roll speed control of twin-roll thin strip continuous casting, the mostimportant thing is to control the solidification end point in the optimal position.Research shows that the roll speed approximate linear relationship with the surfacetemperature of thin strip at the exit of casting machine. The greater the roll speed thehigher the temperature and more easily broken, the lower the roll speed the lower thetemperature and more easily cracked or mid-seizing.Two model of the solidification end point is designed, first, through the infraredtemperature sensor sampling the temperature of the cooling roll contact with shellinterface, the model about the optimal position of solidification end point and interfacetemperature is established by using the theory of rapid solidification. Second, throughthe thermal imager sampling the thermal radiation image of molten pool temperaturefield distribution, directly determine the solidification end point after image processing.Model parameters are respectively interface temperature and the number of the grid，solved the problem that the solidification end location cannot be directly measured andthe accuracy of the model is enhanced.Two cooling roll speed synchronization control is realized by using the differentialspeed regulator with servo motor and frequency converter. Early adaptive model isrealized by using MRAC，and long-term self-learning model is realized by usingexponential smoothing. These models solved the problem that the roll speed cannot beaccurately adjusted real-time with interfering factors. The model is convenient forcomputer control and meets the requirement of control accuracy, so that an optimalsolution of the production of high quality thin strip is provided.