Control system and method for controlled object in time variant system with dead time, such as single crystal production device by czochralski method
US8150784B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 2006 |
| Grant date | Apr 3, 2012 |
| Priority date | — |
| Expiry date | Jun 10, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B29/06
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.