以非線性模型為基礎之熱軋廠精軋區溫度控制

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

楊世州(Shih-Chou Yung)

指導教授 ： 李 穎

元智大學/工程學院/電機與資訊工程研究所/碩士(1997年)

摘要

本論文是針對熱軋廠精軋區進行溫度控制，保留原本非線性時變
的精軋區熱傳模型特性而不將其線性化。為求控制解，一般是將非線
性模型線性化為線性模型，另一種方式是採用具有局部線性規則的模
糊模型。在本問題中，我們發現可直接使用熱傳模型來設計控制器，
不須轉換成線性模型或模糊模型。我們提出以熱傳模型為基礎的最佳
化控制器，以及根據最佳化控制所求得的PID控制器。如果在特殊情
況下不能以熱傳模型求出控制解，則可將其轉換為具有幾個局部線性
規則的模糊模型，保留原有模型非線性特性且必可求得控制解。我們
也提出以模糊模型為基礎的最佳化控制器，以及根據最佳化控制器所
求得的PID控制器。我們所提出的控制器與把熱傳模型線性化後所求
得的控制器相比，性能較佳，而且設計容易，不需經由試誤法即可得
到理想的控制器參數。

關鍵字

非線性模型 ； 熱軋製程 ； 溫度控制 ； 最佳化控制 ； PID控制

並列摘要

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.

並列關鍵字

nonlinear model ； hot rolling process ； temperature control ； optimal control ； PID control

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