scholarly journals Robust Backstepping Control for Cold Rolling Main Drive System with Nonlinear Uncertainties

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xu Yang ◽  
Kai-xiang Peng ◽  
Chao-nan Tong
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
Linear Time ◽  
External Disturbance ◽  
Rolling Process ◽  
Drive System ◽  
Disturbance Attenuation ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Main Drive System

The nonlinear model of main drive system in cold rolling process, which considers the influence with parameter uncertainties such as clearance and variable friction coefficient, as well as external disturbance by roll eccentricity and variation of strip material quality, is built. By transformation, the lower triangular structure form of main drive system is obtained. The backstepping algorithm based on signal compensation is proposed to design a linear time-invariant (LTI) robust controller, including a nominal controller and a robust compensator. A comparison with PI controller shows that the controller has better disturbance attenuation performance and tracking behaviors. Meanwhile, according to its LTI characteristic, the robust controller can be realized easily; therefore it is also appropriated to high speed dynamic rolling process.

Coupling Dynamic Model and Control of Chatter in Cold Rolling

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Xu Yang ◽  
Chao-nan Tong
Keyword(s):  
Cold Rolling ◽  
Dynamic Model ◽  
Process Model ◽  
Stand Structure ◽  
External Disturbance ◽  
Multiple Input Multiple Output ◽  
Rolling Process ◽  
Disturbance Attenuation ◽  
Input Multiple Output ◽  
Strip Quality

The dynamic model of 4-h mill, which couples with the rolling process model, the mill roll stand structure model, and the hydraulic servo system model, is built by analyzing the vibration process of cold rolling. By linearization, the multiple input multiple output linear transfer function matrix model of single stand 4-h cold mill system is obtained. With the consideration of strip quality, the model of strip thickness control system is established in a simplified form. Meanwhile, the robust controller based on quantitative feedback theory is designed for the gauge control model. A comparison with PID controller shows that the controller has better disturbance attenuation performance for parameter uncertainty and external disturbance.

scholarly journals Nonlinear Torsional Vibration Dynamics Behaviors of Rolling Mill’s Multi-DOF Main Drive System under Parametric Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dongying Han ◽  
Peiming Shi ◽  
Kewei Xia
Keyword(s):  
Torsional Vibration ◽  
Joint Angle ◽  
Rolling Process ◽  
Nonlinear Damping ◽  
Drive System ◽  
Nonlinear Stiffness ◽  
Coupled Equations ◽  
Principal Coordinates ◽  
Damping Torque ◽  
Main Drive System

Considering the influence caused by joint angle, nonlinear damping, and nonlinear rigidity, the nonlinear torsional vibration dynamical modeling of the multi-DOF rolling mill’s main drive system is established. To analyze the coupled equations by analytic method, the equations are decoupled by transforming them into principal coordinates. The amplitude-frequency characteristic equations are obtained by multiscale method. Furthermore, numerical example based on the 1780 rolling mill’s main drive system of some Steel Co. is given to illustrate the effects of the resonance on the response of the system. The relationship between amplitude and frequency varies according to the parameters changes of nonlinear stiffness, nonlinear friction damping, torque disturbance, and joint angle. During the rolling process, the limited joint angles range is obtained and the variation rules of the joint angle caused by the nonlinear damping, nonlinear stiffness, and the disturbance torque are gained. The results present that the rolling mill can work more stably with the joint angle at a range from 2° to 8° by controlling the value of parameters. The research results provide a theoretical basis and reference for analyzing torsional vibration of rolling mill’s transmission system caused by joint angle.

Research on the Stress Uniformity of the High Speed Bearing with Heavy Load in Cold Rolling

2014 ◽  
Vol 599-601 ◽  
pp. 422-425
Author(s):  
Zhe Hong ◽  
Bao Shou Sun ◽  
Bin Hu
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
Roller Bearing ◽  
Rolling Process ◽  
Fe Model ◽  
Feed Speed ◽  
Heavy Load ◽  
Tapered Roller Bearing ◽  
Bearing Rings ◽  
Stress Uniformity

An FE model is established on the basis of ABAQUS software for simulating the closed cold rolling process of the high speed TRB (tapered roller bearing) with heavy load. The influences of the feed speed, main roll rotational ratio, and initial angle between two guide rolls on the stress uniformity of the formed bearing rings are studied by evaluating the standard deviation of the Von Mises on all elements in the FE model. The research shows that the stress uniformity of the formed bearing rings decreases with the increment of the feed speed; the stress uniformity increases with the increment of the main roll rotational ratio; and the stress uniformity increases with the increment of the angle between two guide rolls.

scholarly journals H∞ Robust T-S Fuzzy Design for Uncertain Nonlinear Systems with State Delays Based on Sliding Mode Control

2010 ◽  
Vol 5 (4) ◽  
pp. 592 ◽  
Author(s):  
Xizheng Zhang ◽  
Yaonan Wang ◽  
Xiaofang Yuan
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Disturbance Attenuation ◽  
Linear Matrix ◽  
Parameter Uncertainties ◽  
Mode Control ◽  
Disturbance Attenuation Level ◽  
Takagi Sugeno

This paper presents the fuzzy design of sliding mode control (SMC) for nonlinear systems with state delay, which can be represented by a Takagi-Sugeno (TS) model with uncertainties. There exist the parameter uncertainties in both the state and input matrices, as well as the unmatched external disturbance. The key feature of this work is the integration of SMC method with H∞ technique such that the robust asymptotically stability with a prescribed disturbance attenuation level γ can be achieved. A sufficient condition for the existence of the desired SMC is obtained by solving a set of linear matrix inequalities (LMIs). The reachability of the specified switching surface is proven. Simulation results show the validity of the proposed method.

Modeling and Optimization of Rolling Process: A Multi-Objective Approach

2020 ◽  
Vol 19 (02) ◽  
pp. 343-364
Author(s):  
S. Panda ◽  
S. N. Panda
Keyword(s):  
Cold Rolling ◽  
Film Thickness ◽  
Temperature Rise ◽  
High Speed ◽  
Rolling Process ◽  
Response Analysis ◽  
Strip Rolling ◽  
Multi Objective ◽  
Inlet Zone ◽  
Cold Strip Rolling

In a high-speed cold strip rolling process, it is necessary to optimize the process parameters for improved quality in the product. In this study, two separate multi-objective optimization problems for a cold rolling process are formulated. The objectives in one of the cases are minimum isothermal film thickness and film temperature rise in the inlet zone and in another case it is minimum thermal film thickness and film temperature rise in the inlet zone. Particle swarm optimization algorithm has been used for solving the optimization problem. The key input parameters for the cold rolling process are identified and prioritized through the convergence study and the coefficient of variation analysis. A response analysis is performed on the critical input variables. This study assists the process engineer to understand the lubrication in cold strip rolling at high speed and select an appropriate lubricant for a given combination of strip and rolls.

Torsional Vibration Analysis of Drive System for 6-High Cold Rolling Mill

2013 ◽  
Vol 721 ◽  
pp. 572-578
Author(s):  
Yu Hou ◽  
Zhi Jing Zhang ◽  
Yan Xia Guo ◽  
Jiu Qiang Feng ◽  
Jie Luo
Keyword(s):  
Cold Rolling ◽  
Torsional Vibration ◽  
Rolling Mill ◽  
Weak Link ◽  
Drive System ◽  
Cold Rolling Mill ◽  
Vibration Model ◽  
The Impact ◽  
Main Drive System ◽  
Biting Time

The torsional vibration model of main drive system for 6-high cold rolling mill was established. Calculation formula of torque amplification factor (TAF) of main drive system was put forward when the clearance exists or not. The TAF-curve, changing by the biting time of blank, was drawn, and whether torsional vibration could cause mechanical failure in weak link of main drive system was judged. The TAF variation with the biting time of blank was analyzed when the clearance exists. The method to reduce TAF was proposed before the clearance was eliminated, and the effect caused by the impact on main drive system was alleviated.

scholarly journals System dynamics of a pipe pilger CRM working stand

2019 ◽  
Vol 75 (6) ◽  
pp. 725-734
Author(s):  
S. P. Rakhmanov ◽  
V. V. Povorotniy
Keyword(s):  
Optimal Design ◽  
Cold Rolling ◽  
High Speed ◽  
Rational Design ◽  
System Analysis ◽  
High Efficiency ◽  
Rolling Process ◽  
Calculation Algorithm ◽  
Cold Rolling Mills ◽  
Analysis Of Dynamics

Efficiency of the pilger cold rolling of pipes process realization can be increased both by perfection of the rolling process and by a selection of rational parameters of the base technological equipment and the mills functioning regimes. Particular attention should be paid to the increase of reliability of functioning, increase of high-speed and productivity of pipe cold rolling mills (CRMs). Results of the system analysis of dynamics of pipe CRM working stand of various designs presented. A calculation algorithm elaborated and differential equations of the pipe CRM working stand obtained. Pictures of dynamic motions for selected pipe CRM working stand obtained. The analysis of theoretical studies showed, that for stabilization of the stand base elements it is necessary to increase the rigidity of the working stand correspondent elements. It was shown, that the stand rigidity increase reached by arrangement longitudinal bridge of variable thickness, connecting the internal and external structure’ casing. An optimal design roller actuator elaborated. Implementation of the actuator will enable to accomplish the technological process more effectively, since the unit’ elements can adopt all possible inaccuracy of the working stand manufacturing and assembling, as well as housing post deformation. It was ascertained, that the roller actuator of optimal design, above all, plays a role of an emergency gear of the pipe CRM working stand. The studies revealed that increase of productivity and quality of the manufactured products reached mainly by application of the working stand of rational design at the pipe CRM. The industrial running the modified variant of working stand design during eight years to roll hard-deformed steels and alloys confirm its high efficiency at production of precision high quality pipes.

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