Control System and Method for Controlled Object in Time Variant System With Dead Time, Such As Single Crystal Production Device by Czochralski Method

摘要

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. A gain scheduled sliding mode control unit (212) performs a gain scheduled sliding mode control operation based upon the state variable value x(t+Ld) at the predicted future point in time, an output deviation z(t+Ld) at the future point in time, the time constant, and the set value of the process gain at the future point in time, to determine the manipulated variable u_T of the controlled object (200).