28 results on '"Dianhua, Zhang"'
Search Results
2. Ensemble Learning Based Methods for Crown Prediction of Hot-Rolled Strip
- Author
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Dianhua Zhang, Guangtao Li, Xing Lu, and Dianyao Gong
- Subjects
Mechanics of Materials ,business.industry ,Computer science ,Mechanical Engineering ,Crown (botany) ,Bayesian optimization ,Materials Chemistry ,Metals and Alloys ,Structural engineering ,Hot strip rolling ,business ,Ensemble learning ,Hot rolled - Published
- 2021
3. Looper-gauge Integrated Control in Hot Strip Finishing Mill Using Inverse Linear Quadratic Theory
- Author
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Yaohui Hu, Wen Peng, Jie Sun, Yin Fangchen, Dianhua Zhang, and Yunjian Hu
- Subjects
Mechanics of Materials ,Mechanical Engineering ,Mathematical analysis ,Materials Chemistry ,Metals and Alloys ,Inverse ,Mill ,Linear quadratic ,Gauge (firearms) ,Mathematics - Published
- 2019
4. A New Data-driven Roll Force and Roll Torque Model Based on FEM and Hybrid PSO-ELM for Hot Strip Rolling
- Author
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Dianyao Gong, Dianhua Zhang, Zhenhua Wang, and Wen Peng
- Subjects
Materials science ,Mechanics of Materials ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys ,Torque ,Mechanical engineering ,Hot strip rolling ,Finite element method ,Extreme learning machine ,Data-driven - Published
- 2019
5. Optimal control of tension and thickness for tandem cold rolling process based on receding horizon control
- Author
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Yunjian Hu, Shu Zong Chen, Dianhua Zhang, Xin Zhang, Jie Sun, and Wen Peng
- Subjects
010302 applied physics ,Materials science ,Tandem ,Tension (physics) ,Mechanical Engineering ,Horizon ,0211 other engineering and technologies ,Metals and Alloys ,Process (computing) ,02 engineering and technology ,Optimal control ,Interference (wave propagation) ,01 natural sciences ,Mechanics of Materials ,Control theory ,0103 physical sciences ,Materials Chemistry ,021102 mining & metallurgy - Abstract
Tandem cold rolling is a high-speed, high-efficiency, and complex production process. In some cases, minor interference or disoperation may result in large economic losses. To improve control perfo...
- Published
- 2019
6. Design of a Kind of Backup Roll Contour Used in Four-High CVC Hot Strip Mill
- Author
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Guangtao Li, Dianyao Gong, Xing Lu, Zhenhua Wang, and Dianhua Zhang
- Subjects
Hot strip mill ,Mechanics of Materials ,Computer science ,Mechanical Engineering ,Backup roll ,Materials Chemistry ,Metals and Alloys ,Mechanical engineering ,Contact pressure - Published
- 2019
7. Stability Analysis of a Nonlinear Coupled Vibration Model in a Tandem Cold Rolling Mill
- Author
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Guangtao Li, Xing Lu, Jie Sun, Dianhua Zhang, and Wang Zhenhua
- Subjects
Article Subject ,0211 other engineering and technologies ,02 engineering and technology ,STRIPS ,01 natural sciences ,law.invention ,Physics::Fluid Dynamics ,High Energy Physics::Theory ,symbols.namesake ,law ,0103 physical sciences ,Vertical direction ,Mill ,Point (geometry) ,010301 acoustics ,Bifurcation ,021102 mining & metallurgy ,Civil and Structural Engineering ,Mathematics ,Hopf bifurcation ,business.industry ,Mechanical Engineering ,Structural engineering ,Physics::Classical Physics ,Geotechnical Engineering and Engineering Geology ,Condensed Matter Physics ,lcsh:QC1-999 ,Vibration ,Nonlinear system ,Mechanics of Materials ,symbols ,business ,lcsh:Physics - Abstract
Mill chatter in tandem cold rolling mill is a major rejection to the quality and production of the strips. In most mill vibration models, either the roll mass is usually limited to vibrate in vertical direction and vertical-horizontal directions, or the multiple rolls system is simplified to a single mass system. However, the torsional chatter is also a typical type of mill chatter, and the presence of intermediate roll and backup roll will affect the overall vibration of the mill structure system. In this paper, a newly cold rolling mill vibration model coupled with the dynamic rolling processing model and nonlinear vibration model is proposed with the consideration of dynamic coupling and nonlinear characteristics of the rolling process, multiroll equilibrium, and roll movement in both vertical-horizontal-torsional directions. By using Hopf bifurcation theorem and Routh–Hurwitz determinant, the existence of the Hopf bifurcation point of the mill vibration system and bifurcation characteristics are analyzed. At last, the influence of different rolling conditions on the stability of the coupled mill system is investigated, and these results can also be used to design an optimum rolling schedule and determine the appearance of mill chatter under certain rolling conditions.
- Published
- 2019
8. A novel approach to improve the computing accuracy of rolling force and forward slip
- Author
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He-nan Bu, Dianhua Zhang, and Zhu-wen Yan
- Subjects
010302 applied physics ,Friction coefficient ,Engineering ,business.industry ,Mechanical Engineering ,Flatness (systems theory) ,Rolling resistance ,0211 other engineering and technologies ,Metals and Alloys ,Evolutionary algorithm ,Mechanical engineering ,02 engineering and technology ,Deformation (meteorology) ,01 natural sciences ,Mechanics of Materials ,Control system ,0103 physical sciences ,Line (geometry) ,Materials Chemistry ,business ,021102 mining & metallurgy - Abstract
In cold strip rolling control system, rolling force and forward slip are the prerequisites for the model setting calculation, and the deformation resistance and friction coefficient are the main parameters that affect their predictions. A new method based on objective function is first proposed in this paper to improve the calculation accuracy of rolling force and forward slip, and the deformation resistance and friction coefficient are taken as optimisation variables. Using the multi-population co-evolutionary algorithm to solve the objective function, the required rolling force and forward slip are obtained. The pre-set values of rolling force and roller line speed are compared with the actual measured ones in a 1450 mm five-stand tandem cold mill and other researcher’s method. Results show that the calculated values are in fair agreements with the on-line measured ones, and the thickness and flatness accuracy of the final product are improved.
- Published
- 2017
9. Vibration analysis and numerical simulation of rolling interface during cold rolling with unsteady lubrication
- Author
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Xu Li, Qinglong Wang, Dianhua Zhang, and Lei Cao
- Subjects
Work (thermodynamics) ,Materials science ,Computer simulation ,Tension (physics) ,Mechanical Engineering ,02 engineering and technology ,Surfaces and Interfaces ,Mechanics ,Tribology ,Physics::Classical Physics ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,Physics::Fluid Dynamics ,Stress (mechanics) ,Vibration ,Viscosity ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Lubrication ,0210 nano-technology - Abstract
The friction characteristics of rolling interface play a considerable role in rolling stability. In this work, vertical vibration speed is introduced into the Karman equation. An unsteady lubrication model considering entraining and squeezing effect is proposed. Additionally, a dynamic chatter model is developed by coupling the improved rolling force and unsteady lubrication model. The verification results at the micro- and macro-scales indicate that this chatter model has high accuracy. The effects of main process parameters, such as reduction, back tension and viscosity, on the mill stability were analyzed. Moreover, the changes in parameters and tribological characteristics due to unstable rolling process were investigated. The work concludes that the rapid change of lubrication state and friction stress result in vibration intensification.
- Published
- 2021
10. Application of hyperbolic sine velocity field for the analysis of tandem cold rolling
- Author
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Jie Sun, Yuan-Ming Liu, Qing-Long Wang, Dianhua Zhang, Yu-Kun Hu, and De-Wen Zhao
- Subjects
0209 industrial biotechnology ,Engineering ,Field (physics) ,business.industry ,Mechanical Engineering ,Flatness (systems theory) ,Hyperbolic function ,02 engineering and technology ,Surface finish ,Mechanics ,Physics::Classical Physics ,Condensed Matter Physics ,Flattening ,Physics::Fluid Dynamics ,Stress (mechanics) ,020303 mechanical engineering & transports ,020901 industrial engineering & automation ,Classical mechanics ,0203 mechanical engineering ,Mechanics of Materials ,Torque ,General Materials Science ,Vector field ,business ,Civil and Structural Engineering - Abstract
Automatic control systems for tandem cold rolling are constantly being applied due to consumers’ requirements: good flatness and surface finish, accurate strip thickness, and consistent metallurgical properties. And those requirements are related to accurate prediction of the roll force directly. A novel analytical approach to predict roll force in tandem cold rolling is proposed based on elastic and plastic mechanics. A hyperbolic sine velocity field is firstly proposed to get the required minimum roll force in plastic deformation zone in this paper. The field, Inscribed Dodecagon (ID) yield criterion and the co-line vector inner product method are applied to integrate the analytical expression of total deformation power functional. The values of roll torque, roll force and stress effective factor are obtained considering the effect of roll flattening on the roll force. A good agreement between theoretical predictions of roll force and other researchers’ models, especially on-line measured roll force in a tandem cold rolling plant, verifies that the proposed mathematical model is efficient and stable, and the model can be considered to be applied in cold rolling. Besides, the effects of rolling parameters on location of neutral point and stress effective factor are discussed respectively.
- Published
- 2016
11. Optimal multi-variable flatness control for a cold rolling mill based on a box-constraint optimisation algorithm
- Author
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Hong-Min Liu, Pengfei Wang, Jie Sun, Dongmiao Qiao, and Dianhua Zhang
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Mechanical Engineering ,Flatness (systems theory) ,Feasible region ,Metals and Alloys ,Univariate ,02 engineering and technology ,Multi variable ,020501 mining & metallurgy ,020901 industrial engineering & automation ,0205 materials engineering ,Mechanics of Materials ,Control theory ,Control system ,Materials Chemistry ,Rolling mill ,Optimisation algorithm ,Actuator ,Mathematics - Abstract
As the flatness control system is a multi-variable control system, the key issue for high-precision flatness is the determination of the optimal adjustments of flatness actuators. In order to determine these the first step is the establishment of a multi-variable control model in the flatness control process, by which the actual flatness control problem has been reduced to a non-linear optimisation problem with box-constraints. Around this optimisation problem, characteristics and applicability of current optimisation algorithms were analysed. Based on the coordinate descent method, a new multi-variable optimisation algorithm with global convergence was proposed. In the algorithm, the problem was transformed into a series of univariate optimisations which could be solved by sequentially searching along coordinate directions. In order to make the objective function decrease rapidly, and ensure that each iteration are carried out within the feasible region, the accelerating step method is adopted to determi...
- Published
- 2016
12. Microstructure and Mechanical Properties of Semi-continuous Equal-channel Angular Extruded Interstitial-free Steel
- Author
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Dianhua Zhang, Bo Yan, and Si-hai Jiao
- Subjects
Materials science ,Metallurgy ,Metals and Alloys ,02 engineering and technology ,Microstructure ,Grain size ,020501 mining & metallurgy ,0205 materials engineering ,Mechanics of Materials ,Ultimate tensile strength ,Materials Chemistry ,Extrusion ,Elongation ,Severe plastic deformation ,Electron backscatter diffraction ,Tensile testing - Abstract
An innovative method called semi-continuous equal-channel angular extrusion (SC-ECAE) has been developed to produce ultrafine grained steel by inducing severe plastic deformation. In contrast to the external forces that are exerted on specimens in traditional ECAE, the driving forces are applied on the dies in the novel SC-EACE process. Commercial interstitial-free steel sheets with width of 160 mm and thickness of 2 mm were processed repeatedly to various passes at room temperature using this method. The microstructural evolution was characterized using high-resolution electron backscatter diffraction (EBSD), and the mechanical properties were investigated by tensile testing. The EBSD images indicated that the fraction of high-angle boundaries (HABs) began to increase gradually after four passes; after six passes, elongated HAB structures with nearly submicron-scale average spacings were formed. The tensile testing results showed that strengthening was accompanied by a decrease in tensile ductility, but no significant anisotropy was observed. After 10 passes, a final HAB fraction of about 90% and an overall grain size of 0. 55 µm, yield strength of 638. 7 MPa, an ultimate tensile strength (UTS) of 710. 3 MPa, and a total elongation of 12. 0% were obtained.
- Published
- 2016
13. Analysis of Asymmetrical Rolling of Unbonded Clad Sheet by Slab Method Considering Vertical Shear Stress
- Author
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Dianhua Zhang, Hongyu Wang, and De-wen Zhao
- Subjects
Stress (mechanics) ,Materials science ,Mechanics of Materials ,business.industry ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys ,Slab ,Structural engineering ,Composite material ,business ,Vertical shear - Published
- 2015
14. Modeling and Analysis of Interstand Tension Control in 6-high Tandem Cold Rolling Mill
- Author
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Xin Zhang, Hao-yuz Zhang, Shu-zong Chen, Xi-wen Zhang, Jie Sun, and Dianhua Zhang
- Subjects
Engineering ,Tandem ,business.industry ,Tension (physics) ,media_common.quotation_subject ,Mass flow ,Metals and Alloys ,Process (computing) ,Mechanics ,Physics::Fluid Dynamics ,Filter (large eddy simulation) ,symbols.namesake ,Mechanics of Materials ,Materials Chemistry ,Bilinear transform ,Calculus ,Taylor series ,symbols ,Eccentricity (behavior) ,business ,media_common - Abstract
The interstand tension control is one of the most important ways to meet tight tolerances for strip product quality during tandem cold rolling process. Using coordinate analysis and parabolic approximation for the mass flow balance principle, the strip velocities eliminating the use of forward slips and backward slips were calculated. In order to reduce the effect of roll eccentricity on the tension measurement, a filter based on bilinear transformation was designed. Applying a first-order Taylor series approximation, the transfer function matrix model of interstand tension stress was derived. The actual measurements on-site and the final calculation results showed that the established model had high calculation accuracy and was beneficial for interstand tension control of tandem cold rolling process.
- Published
- 2014
15. Simplified Weighted Velocity Field for Prediction of Hot Strip Rolling Force by Taking into Account Flatening of Rolls
- Author
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Wen Peng, Dianhua Zhang, Dewen Zhao, Jiu-jing Xu, and Cao Jianzhao
- Subjects
Materials science ,Field (physics) ,Metals and Alloys ,Radius ,Mechanics ,Deformation (meteorology) ,Flattening ,Power (physics) ,Stress (mechanics) ,Classical mechanics ,Mechanics of Materials ,Materials Chemistry ,Shape factor ,Power function - Abstract
The weighted velocity field was simplified for analysis of hot strip rolling. Using the field and GM (geometric midline) yield criterion, the deformation power, friction power and shear power were obtained respectively. Summing the partial power contributions, the total deformation power for strip rolling was presented. Then, by minimizing the power function, the rolling force was obtained; meanwhile, considering the effect of roll elastic flattening, iterative calculation of the roll radius was carried out until the radius was convergent. On-line data were compared with the calculated results to verify the model accuracy. It was indicated that the calculated rolling forces were basically in agreement with the measured ones since the maximum error was less than 10.0%. Moreover, the effects of various rolling conditions such as thickness reduction, friction factor and shape factor, upon separating force, location of neutral angle, and stress state coefficient were discussed systematically.
- Published
- 2014
16. Optimization of Temperature and Force Adaptation Algorithm in Hot Strip Mill
- Author
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Dianhua Zhang, Wen Peng, Zi-ying Liu, Xi-lin Yang, and Cao Jianzhao
- Subjects
Materials science ,Simplex algorithm ,Distribution (number theory) ,Mechanics of Materials ,Control theory ,Control system ,Industrial production ,Materials Chemistry ,Metals and Alloys ,Process (computing) ,Penalty method ,Deformation (meteorology) ,Adaptation (computer science) - Abstract
In the hot strip rolling control system, the temperature distribution and deformation resistance are the main parameters affecting prediction of rolling force. In order to improve the model prediction precision, an optimization algorithm based on objective function was put forward, in which the penalty function index was adopted. During the adaptation process, the temperature distribution and deformation resistance were taken as the optimized parameters, and the Nelder-Mead simplex algorithm was used to search the optimal solution of the objective function. Furthermore, the temperature adaptation and force adaptation were solved simultaneously. Application results show that the method can improve the accuracy of the rolling force model obviously, and it can meet the demand of the industrial production and has a good application prospect.
- Published
- 2014
17. Analysis of Hot Tandem Rolling Force with Logarithmic Velocity Field and EA Yield Criterion
- Author
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Wen Peng, Cao Jianzhao, Shun-hu Zhang, Shu-zong Chen, Dewen Zhao, and Dianhua Zhang
- Subjects
Yield (engineering) ,Materials science ,Field (physics) ,Metals and Alloys ,Mechanics ,Power (physics) ,Physics::Fluid Dynamics ,Stress (mechanics) ,Mechanics of Materials ,Materials Chemistry ,Calculus ,Torque ,Vector field ,Shape factor ,Reduction (mathematics) - Abstract
In order to analyze the hot tandem rolling force, a new logarithmic velocity field is proposed. Using the field and linear EA (equal area) yield criterion, the plastic deformation power for plate rolling is analyzed, and the friction power is obtained based on the co-line vector inner product method. Then analytical solution of plate rolling power functional is obtained. Finally, by minimizing the power functional, the rolling force and torque are received Compared with those measured ones in hot tandem rolling on-line, the calculated rolling forces are in good agreement with the actual measured ones since the maximum error is less than 12%. Moreover, the effects of various rolling conditions such as thickness reduction, friction factor and shape factor, upon separating force, location of neutral angle, and stress state coefficient are discussed systematically.
- Published
- 2014
18. Actuator Efficiency Adaptive Flatness Control Model and Its Application in 1250 mm Reversible Cold Strip Mill
- Author
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Pengfei Wang, Hong-Min Liu, Yan Peng, Jun-sheng Wang, and Dianhua Zhang
- Subjects
Computer Science::Robotics ,Materials science ,Adaptive control ,Mechanics of Materials ,Control theory ,Control system ,Flatness (systems theory) ,Metallic materials ,Materials Chemistry ,Metals and Alloys ,Strip mill ,Actuator ,Closed loop feedback - Abstract
The existing research of the flatness control for strip cold rolling mainly focuses on the calculation of the optimum adjustment of individual flatness actuator in accordance with the flatness deviation, which is used for general flatness control. As the basis of flatness control system, the efficiencies of flatness actuators provide a quantitative description to the law of flatness control. Therefore, the determination of actuator efficiency factors is crucial in flatness control. The strategies of closed loop feedback flatness control and rolling force feed-forward control were established respectively based on actuator efficiency factors. For the purpose of obtaining accurate efficiency factors matrixes of flatness actuators, a self-learning model of actuator efficiency factors was established. The precision of actuator efficiency factors can be improved continuously by the input of correlative measured flatness data. Meanwhile, the self-learning model of actuator efficiency factors permits the application of this flatness control for all possible types of actuators and every stand type. The application results show that the self-learning model is capable of obtaining good flatness.
- Published
- 2013
19. Algorithm Design and Application of Laminar Cooling Feedback Control in Hot Strip Mill
- Author
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Bai-hong Gao, Li-tao Su, Liang-gui Peng, En-yang Liu, Jie Sun, and Dianhua Zhang
- Subjects
Materials science ,Temperature control ,Feedback control ,Metals and Alloys ,Process (computing) ,PID controller ,STRIPS ,Smith predictor ,law.invention ,Mechanics of Materials ,Control theory ,law ,Control system ,Materials Chemistry ,Algorithm design - Abstract
Feedback control is one of the most important ways to improve coiling temperature control precision during laminar cooling process. Laminar cooling equipments of a hot strip mill and structure of the control system were introduced. Feedback control algorithm based on PI controller and that based on Smith predictor were designed and tested in a hot strip mill respectively. Practical application shows that the feedback control system based on PI controller plays a limited role in improving coiling temperature control precision. The feedback control system based on Smith predictor runs stable and reliable. When the measured coiling temperature deviates from the target value, it can be adjusted to the required range quickly and steadily by Smith predictor feedback control, which improves the coiling temperature control precision greatly, and qualities of hot rolled strips are improved significantly.
- Published
- 2012
20. Calculation Method of Optimal Speed Profile for Hot Plate During Controlled Cooling Process
- Author
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Xiaolin Chen, Yong Tian, Dianhua Zhang, Zhaodong Wang, Jun Wang, and Bing-xing Wang
- Subjects
Mathematical optimization ,Materials science ,Mechanics of Materials ,Homogeneous ,Cooling temperature ,Control system ,Metallic materials ,Materials Chemistry ,Metals and Alloys ,Process (computing) ,Hot plate ,Mechanics ,Cholesky decomposition - Abstract
The healthy and rapid development of the controlled cooling technology was hampered by the uneven cooling phenomenon. During the process of hot plate production, the homogeneous cooling along the length direction of plate was constrained by lots of factors. And because the speed was a flexible control parameter, the calculation method of optimal speed profile was developed based on the measured start cooling temperature and its matrix equation was solved by the Cholesky decomposition method. The optimal speed profile was used in online control system. As a result, the temperature distribution along the plate length direction was relatively uniform, and 95% of measured final cooling temperature difference from the target temperature 700 °C was controlled within ±20 °C.
- Published
- 2011
21. Factors affecting temperature distribution along thickness of plate during cooling process and their control strategies
- Author
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Guodong Wang, Xiao-hui Cai, Dianhua Zhang, and Xianghua Liu
- Subjects
Specific heat ,Water flow ,Chemistry ,Metals and Alloys ,Finite difference method ,Mechanical engineering ,Mechanics ,Thermal conduction ,Cooling time ,Mechanics of Materials ,Metallic materials ,Homogeneity (physics) ,Materials Chemistry ,Physics::Atomic Physics - Abstract
On the basis of the finite difference method, the factors affecting the temperature distribution along the thickness of plate during cooling process were analyzed, which include transformation heat, coefficient of heat conduction, specific heat, carbon content, cooling time, plate thickness, and unit of water flow volume. To ensure the homogenous temperature distribution along the thickness of plate, some cooling strategies, such as interval cooling, stepped cooling, and unsymmetrical cooling of upper and lower surfaces, were applied online. The online results showed that the cooling strategies can improve the temperature homogeneity greatly and the finite difference method can correctly simulate the cooling process.
- Published
- 2010
22. Smith prediction monitor AGC system based on fuzzy self-tuning PID control
- Author
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Jie Sun, Jin Zhang, Dianhua Zhang, De-shun Du, and Li-wei Xu
- Subjects
Engineering ,business.industry ,Metals and Alloys ,PID controller ,Control engineering ,Fuzzy logic ,Smith predictor ,Fuzzy self tuning ,Computer Science::Systems and Control ,Mechanics of Materials ,Robustness (computer science) ,Control theory ,Materials Chemistry ,Rolling mill ,business ,Position control - Abstract
In accordance with the feature of pure delay in monitor AGC system for cold rolling mill, a new fuzzy self-tuning PID Smith prediction controller is developed. The position control model is deduced based on a single stand cold rolling mill, and the fuzzy controller for monitor AGC system is designed. The analysis of dynamic performance for traditional PID Smith prediction controller and fuzzy self-tuning PID Smith prediction controller is done by MATLAB toolbox. The simulation results show that fuzzy self-tuning PID Smith controller has stronger robustness, faster response and higher static accuracy than traditional PID Smith controller.
- Published
- 2010
23. A kind of plate laminar cooling strategy with high response and steady precision
- Author
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Na Zhou, Bing-xing Wang, Dianhua Zhang, and Meng Zhang
- Subjects
Steady state (electronics) ,Materials science ,Mechanics of Materials ,Control theory ,Materials Chemistry ,Metals and Alloys ,Laminar cooling ,Process (computing) ,Realization (systems) ,Stability (probability) ,Instability ,Smith predictor - Abstract
After Smith Predictor being used to laminar cooling system, the control law for integral regulators is introduced. New notion of plate sample length is given for evading the delay time varying with the roll table speed. It is found that the integral algorithm is more controllable for system regulating process and has better steady state precision. Compared with the traditional control strategies, the new control law has faster response speed and higher steady state precision. The controller can be regulated in shorter time and the response is faster than that of routine controller and it can effectively eliminate the oscillatory instability. Owing to its easy realization and high stability, it has been applied to a plate mill. The accuracy of finish cooling temperature can be controlled within ±10 °C.
- Published
- 2010
24. Monitor automatic gauge control strategy with a Smith predictor for steel strip rolling
- Author
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Xu Li, Tao Sun, Dianhua Zhang, and Hao Zhang
- Subjects
Engineering ,business.industry ,Mechanical Engineering ,Metals and Alloys ,Regulator ,Process (computing) ,Control engineering ,Geotechnical Engineering and Engineering Geology ,Transfer function ,Smith predictor ,Strip steel ,Mechanics of Materials ,Control theory ,Gauge (instrument) ,Materials Chemistry ,General Materials Science ,Physical and Theoretical Chemistry ,business ,Block (data storage) - Abstract
The simplified transfer function diagram block for a monitor automatic gauge control (Mon-AGC) system of strip steel rolling process was investigated. The new notion of strip sample length was given. In this way, the delay time varying with the rolling speed was evaded. After a Smith predictor was used to monitor the AGC system, the control laws were deduced for both proportional and integral regulators. The control strategies showed that by choosing the controller parameter P=∞ for both control algorithms each regulator could compensate the whole strip gage error in the first control step. The result shows that the integral algorithm is more controllable for the system regulating process and has a better steady-state precision than the proportional regulator. Compared with the traditional control strategy, the new control laws have a faster response speed and a higher steady-state precision.
- Published
- 2008
25. Cooling efficiency of laminar cooling system for plate mill
- Author
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Na Zhou, Bing-xing Wang, Jun Wang, Ming Yu, and Dianhua Zhang
- Subjects
Online model ,Engineering ,business.industry ,Enthalpy ,Metals and Alloys ,Mechanical engineering ,Mechanics ,Mechanics of Materials ,Heat transfer ,Materials Chemistry ,Laminar cooling ,Mill ,Hot plate ,business ,Cooling efficiency ,First law of thermodynamics - Abstract
Heat transfer was researched from a perspective of the industry application. On the basis of the first law of thermodynamics, the cooling efficiency was deduced from the change of enthalpy inside hot plate. The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail. The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared. The results indicated that the control accuracy of the modified model was increased obviously.
- Published
- 2008
26. Application of neural network to prediction of plate finish cooling temperature
- Author
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Na Zhou, Dianhua Zhang, Guang-ming Cao, Ming Yu, Jun Wang, and Bing-xing Wang
- Subjects
Engineering ,Artificial neural network ,Mechanics of Materials ,business.industry ,Mechanical Engineering ,Cooling temperature ,Control system ,Metallic materials ,Mechanical engineering ,General Materials Science ,Heat transfer coefficient ,business ,Multilayer perception - Abstract
To improve the deficiency of the control system of finish cooling temperature (FCT), a new model developed from a combination of a multilayer perception neural network as the self-learning system and traditional mathematical model were brought forward to predict the plate FCT. The relationship between the self-learning factor of heat transfer coefficient and its influencing parameters such as plate thickness, start cooling temperature, was investigated. Simulative calculation indicates that the deficiency of FCT control system is overcome completely, the accuracy of FCT is obviously improved and the difference between the calculated and target FCT is controlled between −15 °C and 15 °C.
- Published
- 2008
27. Deflection compensation model for flatness measuring roll
- Author
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Jun-sheng Wang, Jiawei Liu, Dianhua Zhang, and Pengfei Wang
- Subjects
Physics::Fluid Dynamics ,Mechanics of Materials ,Control theory ,Deflection (engineering) ,Flatness (systems theory) ,Acoustics ,Metallic materials ,Materials Chemistry ,Metals and Alloys ,Influence function ,Mathematics - Abstract
In flatness measuring system, the flatness measuring signal can be affected by the deflection of flatness measuring roll. The stress on flatness measuring roll was analyzed and a deflection model for the flatness measuring roll was obtained by using the influence function method. The model was developed on the basis of the deformation of flatness measuring roll in rolling process and compensation curve was obtained. The results indicated that the set curve of flatness is in good agreement with the online measured curve of flatness, and good strip flatness can be obtained.
- Published
- 2010
28. Effect of initial crown on shape of hot rolled strip
- Author
-
Jianzhong Xu, Dianhua Zhang, Zhengyi Jiang, Dianyao Gong, Xianghua Liu, and Yu Hu
- Subjects
Engineering ,Physics::Instrumentation and Detectors ,business.industry ,Crown (botany) ,Metallurgy ,Metals and Alloys ,Structural engineering ,Computer Science::Digital Libraries ,Bending force ,Hot rolled ,Shape control ,Calculated result ,Mechanics of Materials ,Metallic materials ,Materials Chemistry ,Influence coefficient ,business - Abstract
Based on the influence coefficient method, the effect of entry strip crown on the shape of hot rolled strip was analyzed using the software of roll elastic deformation simulation. According to the practical condition of a domestic hot rolled strip plant, the unit strip crown change from the first stand to the last stand was calculated when the entry crown of hot strip varies. The calculated result shows that the entry strip crown does not significantly affect the target strip crown at the exit of the last finishing stand in respect to a fixed strip shape control reference (such as bending force). The calculation was analyzed, and the research is helpful in modeling strip shape setup and shape control.
- Published
- 2009
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