Abstract: A device controls an object in a time variant system with a dead time such as a Czochralski method single crystal production device (CZ equipment). The dead time, time constant, and process gain value of an object (CZ equipment) are set. The process gain preset value has time variant characteristics. An output value and its first-order and second-order time differentiated values serve as the state variable. A nonlinear state predicting unit predicts a state variable value at a future time, based upon the current output value, dead time, time constant, and process gain preset value. A gain scheduled sliding mode control unit performs a gain scheduled sliding mode control operation based upon the state variable value at the future time, an output deviation at the future time, the time constant, and the set value of the process gain at the future time, to determine the manipulated variable of the object.

Abstract: To accurately control controlled object in a time variant system with a dead time such as a Czochralski method single crystal production device (CZ equipment). The dead time, the time constant, and the process gain value of a controlled object (CZ equipment) (200) are set. The process gain preset value has specified time variant characteristics. An output value y and its first-order and second-order time differentiated values are used as the state variable x of the controlled object (200). A nonlinear state predicting unit (206) predicts a state variable value x(t+Ld) at a future point in time after the dead time, based upon the current output value y, the dead time, the time constant, and the process gain preset value.