鋼板熱軋輥隙之適應設定

Adaptive Technology for Roll-gap Setup on Hot Strip Mill

黃奕銘(Yi-Ming Huang)

指導教授 ： 陳傳生

元智大學/工程學院/機械工程學系/碩士(2000年)

摘要

鋼板熱軋製程當中，精軋區的軋延機容易因更換不同軋延尺寸或不同材質的鋼板，造成預測設定值誤差過大，增加軋壞(cobble)的發生率。尤其以鋼胚經粗軋後，穿越精軋區的鋼帶頭端(head end)輥隙開度設定較難預測與控制。本文針對鋼帶頭端輥隙開度的最佳化設定，提出以模糊理論為基礎，加上鋼帶頭端的軋延力預測誤差值，設計一動態輥隙設定系統以進行輥隙的適應設定(adaptive)，讓鋼帶能夠順利通過軋機完成軋延，並且提高鋼帶頭端厚度的準確度，期能有效地降低軋延成本。
動態輥隙設定系統是結合軋延數學模型、初始值設定模型和模糊控制器所建立而成。由於是採用離線模擬的方式，因此對於實際的軋延現象，我們以建立非線性的軋延數學模型取代。加上初始值設定模型的建立，即可模擬各種尺寸的軋延現象。至於模糊控制器的功能則是根據模擬出來的頭端軋延力誤差，來判斷頭端厚度誤差的現象，進而對輥隙做適當的調整與修正，以減少厚度的誤差值，提高板厚精度。然而如何了解整個動態輥隙設定系統的實用性，我們則採用中鋼公司所提供的資料進行驗證的工作。最後，從模擬出來的結果發現，動態輥隙設定系統對於鋼帶頭端誤差近50 %的資料有進行修正與改善。

關鍵字

熱軋 ； 鋼板熱軋 ； 輥隙 ； 適應設定 ； 模糊控制理論

並列摘要

The changes in strip thickness or material type could cause significant errors of predicted setup values for finishing mill machines and increase times of strip cobbling in the process of hot strip mill. During sheet bar going through finisher mill, especially, it is very difficult to control and predict the roll-gap of the head end of the strip. This thesis focuses on the optimal roll-gap setup of the head end of a strip and designs a dynamic roll-gap setup system based on the fuzzy control theory and the deviations between the predicted rolling forces and the actual rolling forces, in order to improve the accuracy of head end strip thickness and reduce the production cost.
The dynamic roll-gap setup system includes a rolling mathematical model, an initial setup model and a fuzzy controller. At beginning, we established the non-linear mathematical model for off-line simulation for the actual rolling phenomenon in a hot rolling strip mill. Then, we combined the mathematical model and the initial setup model for simulating the rolling process in any scale of strips. The fuzzy controller can predict the thickness error based on the rules derived from actual production records, and correct the roll-gap adequately by application of fuzzy reasoning based on errors between the predicted rolling forces and the actual rolling forces. Finally, we adopted the on-line data provided by China Steel Corporation, Taiwan to test the practicability of the dynamic roll-gap setup system. The simulation results indicate that the dynamic roll-gap setup system can significantly improve the accuracy of head end strip thickness, more than half of the whole simulation runs reach better thickness accuracy after applying the proposed fuzzy controller.

並列關鍵字

Hot Rolling ； Hot Strip Mill ； Roll gap ； Adaptive Setup ； Fuzzy Control Theory

參考文獻

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[3]Lage, A., et al., “Modeling and Simulation of a Hot Strip Rolling Mill”, Industrial Electronics, Control and Instrumentation, Vol.3, pp.2017-2022, 1994.

[4]Moon, Y.-H., et al. “Improvement of Roll-gap Set-up Accuracy Using a Modified Mill Stiffness from Gaugemeter Diagrams”, Journal of Materials Processing Technology, Vol.70, pp.194-197, 1997.

[5]Oda, T., et al.,“Adaptive Technology for Thickness Control of Finisher Set-up on Hot Strip Mil”, ISIJ International, Vol.35, No.1, pp.42-49, 1995.