Sumco Techxiv Corporation

Tetsu Nagata

Shigeo Morimoto

Junsuke Tomioka

Yutaka Shiraishi

Kenichi Bandoh

Takuji Okumura

Takeshi Kodama

Masaru Shimada

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.

Control system and method for controlled object in time variant system with dead time, such as single crystal production device by czochralski method

Growing community of inventors

Hiratsuka, Japan

Tetsu Nagata