Abstract: Two new types of six-high cold mills, CVC6 and UCMW, are equally equipped with perfect control systems to meet demands for thinner sheet products with better profile and flatness but diverse from each other in strategy of control. To strike a balance between them is the problem for analysis.
Abstract: With more and more process data acquired from manufacturing process, extracting useful information to build empirical models of past successful operations is urgently required to get higher product quality. Clustering is the important data mining methods, where feature extraction is a significant factor to ensure the accurate rate of clustering and classification. As a common non-linear feature extraction method, kernel principal component analysis (KPCA) uses the variance as the information metric, but the variance is not always effective in some cases. Since information entropy is nonlinear and can effectively represent the dependencies of features, the Renyi entropy is used as the information metric to extract the feature in this paper. Simulation data, Tennessee Eastman and hot rolling process data are used for model validation. As a result the proposed method has better performance on feature extraction, compared with traditional KPCA.
Abstract: Took the heavy cylinder rolling mill as subject investigated, which is used to produce the nuclear power cylinder, the large hydrogenation reactor cylinder and the coal liquefaction reactor cylinder. And the cylinder rolling mill has two drive rolls which is different from conventional ring rolling mill. The rolling theory of heavy cylinder rolling mill was researched deeply based on mechanism method, including the biting condition, the plastic penetration condition, the feed condition and the feed velocity condition; the rolling force parameters of heavy cylinder rolling mill with two drive rolls were calculated based on the slip line method (SLM) and finite element method (FEM), and the simulation and industrial experiment were done; the influences of main technology parameters such as feed velocity, friction coefficient and temperature on the rolling force parameters were analyzed. The results show that the error of calculated rolling force and the measured value is less than 5%, which proves that the basic conditions deduced by theory method are correct, the models established based on SLM and FEM are correct. And with the increase of feed velocity, the rolling force increase, after a rolling circle, the rolling force fluctuates at a constant value; with the increase of friction coefficient, the rolling force increase; with the increase of initial temperature, the rolling force decrease.
Abstract: Rolling force is an important technological parameter in designing of the 3700mm cylindrical shell rolling mill. Due to the characteristics of double driving rolls and asynchronous rolling of 3700 mm cylindrical shell rolling mill, the force analysis of the deformation zone is complex. In this study, an analytic method was used to calculate the rolling force. The deformation zone was divided into the forward slip area, the backward slip area and the rub rolling area on the basis of metal flow velocity. The stress equilibrium equations of each area were built. Then the rolling force model of the 3700mm cylindrical shell rolling mill was built and solved, according to the boundary conditions. At the same time, in order to verify the validity of the analysis, the calculated values were compared with the measured in the spot. They have a good agreement, which indicates the calculation accuracy of the model could meet the industry requirements.
Abstract: Hot strip tail flick is an abnormal production phenomenon, which brings many damages. To recognize the tail flick signals from all throwing steel strip signals, a feature extraction method based on morphological pattern spectrum is proposed in this paper. The area between signal curves after multiscale opening operation and the horizontal axis is computed as the pattern spectrum value and it reflects the geometric information differences. Then, support vector machine is used as the classifier. Experimental results show that the total correct rate based on pattern spectrum feature reached 96.5%. Compared with wavelet packet energy feature, the total correct rate is 92.1%. So, the feasibility and availability of this new feature extraction method are verified.
Abstract: This paper expatiated on principles of high pressure abrasive water jet descaling; used GAMBIT and some experience parameters to create the geometry model of the nozzles and the outflow field; used Fluent to simulate the high pressure abrasive water jet under the condition of different jet standoff distance, different impact angle, different mix angle, different abrasive particle size, different abrasive concentration and different abrasive material. Through the analysis of the simulation results, this paper put forward the optimal selection of these parameters.
Abstract: Based on 3D-FEM simulation, a model on influence of strip wave-shape upon the running deviation in the continuous annealing line was developed to improve the strip passing stability. A two-step model of FEM on hot strip rolling calculating the lateral flow of the metal improved the accuracy of strip shape control system.
Abstract: In order to improve the accuracy and performance of long products, increase the metal yield, more better ensure high speed and continuous rolling, the structure and principle of short stress path mill and flying shear which are the key equipments in rolling line are emphasized in our research work. Some new technology method and rational mechanical structure are proposed and has been applied to optimize equipments. The requirements of various products and high quantity production in long milling products are ensured.
Abstract: In response to the characteristics of large time delay, nonlinear, various disturbances in Monitor AGC system for cold rolling mill, a control strategy combining Smith predictor with Active Disturbance Rejection Control (ADRC) is proposed. Approximation ability of Extended State Observer (ESO) to estimate unknown parts of controlled plant model is promoted by model compensated ADRC. Aimed at a 4-high cold rolling mill, simulation analysis for classical Smith predictor monitor AGC and ADRC-Smith predictor Monitor AGC is used. The results indicate that ADRC-Smith predictor Monitor AGC has better performance on robustness and capacity of anti-disturbance.