Automatic flatness control strategy with a Smith predictor for steel strip rolling

2011 ◽  
Author(s):  
Ruicheng Zhang ◽  
Xin Zheng
2012 ◽  
Vol 504-506 ◽  
pp. 1043-1048 ◽  
Author(s):  
Nicolas Legrand ◽  
Nathalie Labbe ◽  
Daniel Weisz-Patrault ◽  
Alain Ehrlacher ◽  
Tomasz Luks ◽  
...  

This paper presents an analysis of roll bite heat transfers during hot steel strip rolling. Two types of temperature sensors (drilled sensor /slot sensor) implemented near roll surface and heat transfer models are used to identify in the roll bite interfacial heat flux, temperature and Heat Transfer Coefficient HTCroll-bite during pilot rolling tests. It is shown that: - the slot type sensor is much more efficient than the drilled type sensor to capture correctly fast roll temperature changes in the bite during hot rolling but life’s duration of the slot sensor is shorter. - average HTCroll-bite, identified with roll sensors temperature signals is within the range 15-26 kW/m2/K: the higher the strip reduction is, the higher the HTCroll-bite is. - scale thickness at strip surface tends to decrease heat transfers from strip to roll in the roll bite. - HTCroll-bite appears not uniform along the roll-strip contact, in contrast to usual assumptions made in existing models - Heat dissipated by friction at roll-strip interface and its partitioning through roll and strip respectively seems over-estimated in the existing thermal roll gap model [1]. Modeling of interfacial friction heat dissipation should be reviewed and verified. The above results show the interest of roll temperature sensors to determine accurately roll bite heat transfers and evaluate more precisely the corresponding roll thermal fatigue degradation.


2014 ◽  
Vol 909 ◽  
pp. 317-322
Author(s):  
Huan Pao Huang ◽  
Ji An Yu ◽  
Qian Su ◽  
Lei Wang

2 × 660MW ultra-supercritical units of O'Brien Power Plant are single configuration of auxiliary pilot project, due to the higher its parameters and performance requirements, it need better control strategies to ensure safe and economical operation. Against traditional cascade PID main steam’s temperature control system delaying large, this article proposed control strategy based on Smith estimated. Main steam’s temperature controlled object inert zone mathematical model can be showed by multi-volume model, and use the improved system for large inertia Smith Predictor to make dynamic parameter control systems improvements. Simulation results of the simulation machine show that: Optimization emperor steam temperature control is in an adjustable range and the policy in separate auxiliary units is feasible.


2020 ◽  
Vol 117 (3) ◽  
pp. 308
Author(s):  
Yin Fang-chen ◽  
Yu Liu-Qi

In the hot strip rolling process, the performance of a monitoring system for automatic gauge control (MN-AGC) is influenced greatly by the model mismatch which is caused by the variation of model parameters values. A constrained dynamic matrix control (CDMC) strategy that includes a prediction model, rolling optimization, and feedback correction was used in the MN-AGC. First, the conventional Smith prediction-based control strategy for the MN-AGC was analyzed. Second, the performance index function and optimal control of the CDMC strategy were determined. Finally, simulations and industrial experiments were conducted. The results showed that both control strategies provided good control performance. When model mismatch occurred, the Smith predictor-based MN-AGC resulted in significant overshoot or even oscillations but the control performance of the CDMC-based MN-AGC was not influenced by changes in the model parameters.


1999 ◽  
Vol 40 (4) ◽  
pp. 433-438 ◽  
Author(s):  
P.J. Hurley ◽  
P.D. Hodgson ◽  
B.C. Muddle

2008 ◽  
Vol 1 (S1) ◽  
pp. 1227-1230 ◽  
Author(s):  
C. Grenier ◽  
P.-O. Bouchard ◽  
P. Montmitonnet ◽  
M. Picard

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