Patent ID: 8202472

Claim:
A method for controlling a ladle to pour molten metal into a mold, the method comprising: supplying a mathematical model describing an electrical voltage supplied to a servomotor for tilting the ladle as a function of a flow rate of the molten metal flowing out of the ladle when the ladle is tilted; measuring an actual electrical voltage supplied to the servomotor; solving an inverse problem of the mathematical model using the measured voltage; estimating the flow rate of the molten metal using a state observer having an exponential damping that uses an extended Kalman filter, based on the measured voltage and a weight of the molten metal poured into the mold, the weight being measured by a weighing equipment and calibrated by eliminating errors caused by a movement of a center of gravity of the ladle; processing the flow rate of the molten metal and a target flow rate of the molten metal with a gain-scheduled PI controller; obtaining a target electrical voltage to be supplied to the servomotor; and controlling the servomotor based on the target electrical voltage.