Papers by Author: Chun Yu He

Abstract: Pilot hot rolling mill is developed with perfect measuring devices and automation system. The hot rolling experimental studies of the plate and strip can be done on this mill. Automation system for this pilot mill is composed with Basic Automation System (BAS), Process Control System (PCS) and Human Machine Interface system (HMI). PC server is used as the PCS hardware, and Microsoft software is used as the operation system and developing software. With the coordination of the functions such as date communication, process tracking, data management, and model calculation, the PCS software function is realized. The effect on the model calculation accuracy with the pilot mill using condition was analyzed. This pilot hot rolling mill gets a lot of application. The practical application shows that the PCS’s setup has a high precision.

Abstract: In the rolling process of heavy plate mill, the longitudinal extension will result in differences at different positions in the lateral direction of rolling pieces. This difference is affected due to some asymmetric rolling conditions, which lead to the camber. Lateral direction of the plate which is based on image processing algorithm is measured by using plate images acquired during rolling process with the help of linear array camera. In combination to camber correction model deducted and camber feedback control system is developed to realize the automatic correction control for camber of plate during production in this paper. Field applications show that this control method is able to reduce human interference and camber curve rate, which is significant in improving the yield of product.

Abstract: Influence function method is a common method to calculate the roll system deformation. It solves after discretizing the rollers load and elastic deformation, but the traditional influence function method doesn't consider whether the width of the rolled piece is equal to the integral multiple of the divided units length, therefore it only can solve approximately, which affects the calculation accuracy. According to the accuracy loss problem of the traditional algorithm, the paper puts forward a solution with advanced structure to deal with the left rolled pieces after division. The solution self-adapts the width changes of the rolled pieces, which not only avoids the problems of increasing the segmentation unit quantity to reduce the influence by edges and reducing the calculation speed of the traditional influence function method, but also improves the calculation accuracy of the model, and raising the level of material properties control.

Abstract: Aiming at the camber problem caused by plate mill’s stiffness difference, this paper put forwards an online compensation method for plate mill’s stiffness difference. Based on the detective actual rolling force in the rolling process, calculate the spring of plate mill’s driving side and non-driving side to get the gap compensation value of plate mill’s stiffness difference. Via plate mill AGC system adjust the two sides’ gap difference online, eliminate additional spring caused by plate mill’s stiffness difference. Online algorithm of plate mill’s stiffness difference embeds in basic automation directly. With the going on of rolling process, update the compensation values constantly according to the changes of rolling force in order to increase the stability and decrease plate camber in the rolling process.

Abstract: According to the requirement to the pilot mill for the cold rolling process research work, new type pilot reverse cold rolling mill is designed. Computer control system, including primary automation system, process automation system and human machine interface (HMI) system, is developed for this mill. Technological control function such as electric position control, hydraulic tension control, automatic gauge control (AGC), and process control functions such as model setup calculation, process tracking, actual data treatment are realized. This new type pilot cold rolling mill has been used successfully in several iron steel companies.

Abstract: Pilot cold rolling mill is the important tool for the cold rolling process researching and new steel grade development. According to the design of the new type direct pulling pilot cold rolling mill, based on the mass flow constant principle, strip exit thickness indirect measurement method is studied. During rolling, strip entry and exit speed can be calculated accurately according to the measured value of two sides’ clamps movement. Data filtering treatment is adopted and program flow chart is designed. Based on the material entry thickness measured manually, exit thickness of all passes can be measured indirectly. This thickness indirect measurement method has been applied successfully on the new type pilot cold rolling mill, and the measurement results show that this method has a good accuracy.

Abstract: For cold rolling process, the theoretical Bland-Ford-Hill model and Hitchcock model are used for the rolling force and roll flatten radius calculation. Friction coefficient and deformation resistance are calculated with empirical regression models. From rolling force model, the recalculation model for the friction coefficient and deformation resistance can be derived. After rolling, with actual measured data, friction coefficient and deformation resistance can be recalculated, and model parameter can be got by regression method. The practical application verifies that the accuracy of rolling force calculation model is good.

Abstract: The model parameters value of deformation resistance determines the prediction accuracy of rolling force model during the plate rolling. According to the influencing factors analysis of rolling force calculation error, the genetic algorithm was introduced into the self-learning method of deformation resistance, and searches the optimal value of deformation resistance on the basic of space exploration and optimization ability of genetic algorithm. The decision variable selection, the coding and decoding, the fitness evaluation and the terminal conditions process were implemented during development process of self-learning system. The results show that the optimization speed and accuracy can meet production requirement.

Abstract: In plate rolling, the existence of some asymmetry rolling conditions, affects the distribution of transversal thickness of rolling pieces, leading to the occurrence of camber phenomenon, which in turn seriously affect the product's material yield. In this paper, based on the images of plates in the production line collected by camera, taking into account the requirements for on-line measurement, filtering noise from image information, use edge detection operator, Hough transform methods and sub pixel edge location method to identify the steel plates, have achieved in-line measurement of camber curvature of plate side. At the same time, combined with camber control model, we have developed camber curvature measurement and control system, realized the automatic correction control of camber curvature of rolling pieces in the production process. Field applications show that this method can reduce the human intervention, will limit the camber curvature of rolling pieces within a certain range, which has great significance for improving the product’s yield.