PURPOSE: To stably control a molten metal level in good condition by correcting at least one of correcting factors multiplied to a correcting quantity command value of an actuater for cancelling the disturbance quantity and added to a feedback calculated signal during the control.
CONSTITUTION: A feedback control loop acted to match the molten metal level detected value L in a mold with a molten metal level reference value Lref is formed. Further, a correcting factor adjuster 56 for including a disturbance canceling control quantity arithmetic part constituted with a correcting signal computing element 52 and a correcting factor multiplier 54 and adjusting the input from the correcting factor multiplier 54 to an adder 42 after adjusting the correcting factor -K in the correcting factor multiplier 54, is arranged. A flow rate disturbance estimated value QW is calculated from a stopper actual positional value (x) decided with a stopper moving characteristic 44 and the molten metal surface level detected value L in the mold through the correcting signal computing element 52. A stopper correcting quantity command value UD for canceling the flow rate disturbance QW developed with the clogging of a nozzle 16 and bulging, etc., is calculate and outputted from the estimated value QW.
KACHI TAKAYUKI
IBARAKI MICHIO
