• 산업공학
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• 제16권2호
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• pp.201-210
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• 2003

The purpose of this research is to develop a scheduling system for CAL (Continuous Annealing Line) in Cold Rolling Mill. Based on CSP (Constraint Satisfaction Problem) technique in artificial intelligence, appropriate algorithms to provide schedules satisfying all the constraints imposed on CAL are designed and developed. Performance tests show that the proposed scheduling system outperforms human operators in case of aggregating the same attributes and minimizing the thickness differences between two adjacent coils.

• Journal of Advanced Marine Engineering and Technology
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• 제35권2호
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• pp.244-251
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• 2011

유한요소법을 통하여 유성압연기에 의한 스테인리스 강관 압연공정을 연구하였다. 3개의 롤에 의한 만네스만 공법을 압연공정에 적용하였다. 보통 유성압연은 냉간가공으로 시작하여 열간가공으로 종료되며, 기존의 압출공정에 비해 공정단축과 생산비절감의 장점을 갖고 있다. 압연공정은 다양하고 복합적인 공정변수를 가지고 있으며, 각각의 변수들은 성형결과에 영향을 미친다. 따라서 유성압연의 다양한 공정변수가 해석에 고려되어야 한다. 본 연구에서는 스테인리스 강관성형의 가능성과 생산성을 검토하였고, 소재예열 및 자전속도, 제품두께 변화를 해석에 반영하였다. 스테인리스 강관 압연공정은 성공적으로 시뮬레이션 되었고 최적의 압연조건을 결정하는데 유용할 것이다.

• 소성∙가공
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• 제25권1호
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• pp.43-48
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• 2016

H-beams are generally produced by hot rolling composed of a Break Down Mill (BDM) and a Finishing Mill (FM). The goal of the current study was to develop BDM rolling of H300ｘ300 beams from blooms slit from slabs. In order to manufacture H300ｘ300 beams, the caliber design and the pass schedule of BDM rolling were proposed for a bloom instead of a beam blank. The proposed BDM caliber design and pass schedule were tested using FE-simulation and pilot tests. For the major shape dimensions, such as flange width, web height, web thickness, as well as BDM rolling loads, a comparative analysis between the FE-simulation and the pilot rolling tests was conducted. The results of FEM analysis and pilot rolling tests showed good consistency. Moreover, BDM rolling loads were predicted to be in the range of allowable rolling loads. It was concluded that the designed BDM rolling is suitable for implementation within current manufacturing capacity.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.491-496
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• 2000

In the tandem cold rolling mill, the quality is very important and requirements for thickness accuracy become more strict. Howerver, the mathematical model for prediction of rolling force was not considered an elastic deformation at the entry and delivery side of the contacted area between the worked roll and rolling strip so that where was so difficult to control of the thickness. To overcome this problem, the mathematical model included an elastic deformation of strip has been developed and applied to the field in order to predict the rolling force. The simulated results showed that the effect of elastic recovery should be included the model, even f the effect of elastic compression was not important.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.1062-1070
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• 2009

The strip shape for the stainless steel process has made an issue of the strip quality, and hence the shape control method is developed at the Sendzimir rolling mill (ZRM). ZRM is a stainless cold rolling mill and has actuators for the shape control. They are first intermediate rolls and top crown rolls, which are controlled horizontally and vertically, respectively. The shape control of the stainless steel rolling process has difficulty in obtaining the symmetrical shape. The objective of the shape control is to minimize the shape deviation and to maintain stable state, which keeps symmetrical shape pattern in the lateral direction. The method of the shape recognition employs a least squares method and neural network. The shape deviation is the difference between the target shape and actual shape and is controlled by the fuzzy shape control. The fuzzy shape control using operator's informative knowledge is proposed in this paper. The experiments are carried out online for various stainless materials and sizes. The productivity of the rolling process has increased from 9.0 to 9.4 tons per hour.

• 소성∙가공
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• 제21권7호
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• pp.426-431
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• 2012

The work roll of a Sendzimir mill has a small diameter in comparison to its length, so it is easily deformed by the rolling pressure. It also has a complex back up roll system, so it is difficult to analyze the roll deformation. For this reason in Part I we have developed a model which predicts the radial displacement of the roll. In this paper, we apply the model to a Sendzimir mill and propose a new model for the prediction of the deformed roll profile in a Sendzimir mill. The prediction accuracy of the new model is demonstrated through comparison of the predictions from the FE model.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.142-149
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• 1999

Strip profile and shape control is one of the most important technologies in cold mill, especially for ultra-thin and wide cold strip. The 6-high mills, both of HCMW and UCMW mill, are known to be very effective for the shape controllability. The optimized values of these factors for set-up scheduling were analyzed and found that excellent strip control would be possible by controlling the combination of the influencing factors according to hot coil profile. The important considerations for operation were discussed for individual stand.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.991-997
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• 2013

In this paper, we propose a CFWC (CCD and fuzzy PID based width control) scheme to obtain the desired delivery width margin of a vertical rolling mill in hot strip process. A WMS(width measurement system) is composed of two line scan cameras, an edge detection algorithm, a glitch filter, and so on. A dynamic model of the mill is derived from a gauge meter equation in order to design the fuzzy PID controller. The controller is a self-learning structure to select the PID gains from the error and error rate of the width margin. The effectiveness of the proposed CFWC is verified from simulation results under a width disturbance of the entry in the mill. Using a field test, we show that the performance of the width control is improved by the proposed control scheme.

• 대한기계학회논문집
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• 제19권7호
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• pp.1597-1603
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• 1995

A prediction model on forward slip has been developed for presetting rolling speed of each finish mill stand in the continuous hot strip roduction. Those factors such as neutral point, friction coefficient, volume fractions undergoing width spread, shape of deformation zone at each side of entry and delivery of the rolls were taken into account. To reduce the speed unbalance between adjacent stands a refining method of adjusting friction coefficient has also been developed. On-line application of the model showed a good agreement in rolling speeds between the predictions and the actual measurements, and gave an outstanding improvement in the travelling stability of strip passing through the finishing mill train.

• 대한기계학회논문집A
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• 제24권11호
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• pp.2836-2844
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• 2000

Thickness control of hot-rolled strips has become an important issue in recent years because of the need for improving the quality of the hot-rolled strip. In this study, a modifying method of rolling force set-up with consideration of spread was developed to improve the thickness uniformity at the finishing rolling units in hot rolling. Through the analysis of real production data it was found that the accuracy of the rolling force determined from the finishing mill set-up (FSU) model dominantly governed the thickness uniformity in rolled plates at the front. Based on this analysis , several examples were selected to calculate the spread of rolled plate using three dimensional rigid thermo-viscoplastic finite element program. FE analysis results were used to train the neural network system that can predict the spread hot-rolled plate and the rolling force was modified based on the predicted value of spread. The modified rolling forces were closer to the measured rolling force so it can be expected that the accuracy of thickness uniformity of hot-rolled plate will be improved.