Temperature Control based on Nonlinear Model for Hot Rolling Process during Finishing Milling

• Main Authors: Shih-Chou Yung, 楊世州
• Other Authors: Ying Li
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/73716215507057124226

碩士 === 元智大學 === 電資與資訊工程研究所 === 86 === This thesis investigates the temperature control problem for hotrolling process during finishing milling. We aim to preserve the nonlinear time-varying characteristics of the plant model in controller design. When the plant model is nonlinear, the common approach in controller design is to linearize the model; an alternative is to convert the model into a fuzzy model with locally linear rules. In our problem, we find that the nonlinear thermal model can be used directly for controller design. It is unnecessary to linearize the model or convert it into a fuzzy model. We propose optimal controllers based on the thermal model, and PID controllers based on optimal control solution. In the special case when the thermal model cannot provide the control solution, it can be converted into a fuzzy model. With the locally linear rules, control solutions for fuzzy models can always be found, and model nonlinearity is preserved. We also propose optimal controllers based on the fuzzy model and the related PID controllers. Compare to the controllers obtained after model linearization, our controllers perform better and are easier to design. Ideal controller parameters can be obtained directly without trials and errors.