Controlling the looper height and strip tension is important in hot strip mills because these variables affect both the strip quality and strip threading. Many researchers have proposed and applied a variety of contro...Controlling the looper height and strip tension is important in hot strip mills because these variables affect both the strip quality and strip threading. Many researchers have proposed and applied a variety of control schemes for this problem, but the increasingly strict market demand for strip quality requires further improvements. This work describes a dynamic matrix predictive control(DMC) strategy that realizes the optimal control of a hydraulic looper multivariable system. Simulation experiments for a traditional controller and the proposed DMC controller were conducted using MATLAB/Simulink software. The simulation results show that both controllers acquire good control effects with model matching. However, when the model is mismatched, the traditional controller produces an overshoot of 32.4% and a rising time of up to 2120.2 ms, which is unacceptable in a hydraulic looper system. The DMC controller restricts the overshoot to less than 0.08%, and the rising time is less than 48.6 ms in all cases.展开更多
High control performances cannot be obtained by most of the existing looper-tension control approaches through only considering controller designs based on continuous time models, which cannot meet the requirements of...High control performances cannot be obtained by most of the existing looper-tension control approaches through only considering controller designs based on continuous time models, which cannot meet the requirements of modern computer control systems with high control accuracy. In order to solve the above problems, a state feedback H∞ control method based on a discrete-time model for looper-tension control systems in hot rolling mills is presen- ted. The considered system is approximated by a discrete-time loope∞tension control system model. Based on a Lya- punov functional method, a state feedback H∞ control law is developed which makes the closed-loop system asymp totically stable with guaranteed H∞ performance. The controller gains are obtained by solving a set of linear matrix inequalities （LMIs）. In contrast to the existing results, the proposed approach can obtain good H∞ performance and effectively reduce external disturbances. The strip tension is also less affected by the change of looper angel, so good control performances can be obtained. Moreover, this control scheme is easy to implement, and can be applied to other linear systems. A simulation example with practical parameters is provided to illustrate the effectiveness of the developed method.展开更多
带钢热连轧机中,活套系统属于典型的双输入双输出非线性系统,此类系统存在的解耦控制问题,鉴于此,将模糊自适应整定P I控制策略用于活套控制中。采用对角矩阵解耦原理对活套系统进行解耦,给出了活套解耦系统的传递函数表达式。设计了一...带钢热连轧机中,活套系统属于典型的双输入双输出非线性系统,此类系统存在的解耦控制问题,鉴于此,将模糊自适应整定P I控制策略用于活套控制中。采用对角矩阵解耦原理对活套系统进行解耦,给出了活套解耦系统的传递函数表达式。设计了一种带解耦器的模糊自适应P I D控制器,模糊推理模块通过输入活套误差e和误差率e c进行推理。实验表明,模糊自适应P I D控制与传统P I D控制相比,能有效提高活套系统的动态性能和稳定性。展开更多
An innovative sliding mode controller for looper and tension control in hot strip finishing mills was developed based on approximately linearized model. Firstly, a fictitious controller of the reduced order subsystem ...An innovative sliding mode controller for looper and tension control in hot strip finishing mills was developed based on approximately linearized model. Firstly, a fictitious controller of the reduced order subsystem was designed according to desired dynamics, by which, the angle and tension loops were decoupled on the sliding manifold. Then, a sliding mode controller was used to validate finite time convergence of the state vector to the manifold which guaranteed the stability and performances of the overall system. This solution was considered owing to its well- known robustness and simplicity characteristics concerning disturbances and unmodelled dynamics. Simulation results showed the effectiveness of the proposed controller compared with conventional ones.展开更多
基金Project(N160704004)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(20131033)supported by the Ph D Start-up Fund of Natural Science Foundation of Liaoning Province,China
文摘Controlling the looper height and strip tension is important in hot strip mills because these variables affect both the strip quality and strip threading. Many researchers have proposed and applied a variety of control schemes for this problem, but the increasingly strict market demand for strip quality requires further improvements. This work describes a dynamic matrix predictive control(DMC) strategy that realizes the optimal control of a hydraulic looper multivariable system. Simulation experiments for a traditional controller and the proposed DMC controller were conducted using MATLAB/Simulink software. The simulation results show that both controllers acquire good control effects with model matching. However, when the model is mismatched, the traditional controller produces an overshoot of 32.4% and a rising time of up to 2120.2 ms, which is unacceptable in a hydraulic looper system. The DMC controller restricts the overshoot to less than 0.08%, and the rising time is less than 48.6 ms in all cases.
基金Item Sponsored by National Natural Science Foundation of China(51374082)National High-Tech Research and Development Program(863Program)of China(2012AA050215)China Iron and Steel Research Foundation(12ZD0850A)
文摘High control performances cannot be obtained by most of the existing looper-tension control approaches through only considering controller designs based on continuous time models, which cannot meet the requirements of modern computer control systems with high control accuracy. In order to solve the above problems, a state feedback H∞ control method based on a discrete-time model for looper-tension control systems in hot rolling mills is presen- ted. The considered system is approximated by a discrete-time loope∞tension control system model. Based on a Lya- punov functional method, a state feedback H∞ control law is developed which makes the closed-loop system asymp totically stable with guaranteed H∞ performance. The controller gains are obtained by solving a set of linear matrix inequalities （LMIs）. In contrast to the existing results, the proposed approach can obtain good H∞ performance and effectively reduce external disturbances. The strip tension is also less affected by the change of looper angel, so good control performances can be obtained. Moreover, this control scheme is easy to implement, and can be applied to other linear systems. A simulation example with practical parameters is provided to illustrate the effectiveness of the developed method.
文摘带钢热连轧机中,活套系统属于典型的双输入双输出非线性系统,此类系统存在的解耦控制问题,鉴于此,将模糊自适应整定P I控制策略用于活套控制中。采用对角矩阵解耦原理对活套系统进行解耦,给出了活套解耦系统的传递函数表达式。设计了一种带解耦器的模糊自适应P I D控制器,模糊推理模块通过输入活套误差e和误差率e c进行推理。实验表明,模糊自适应P I D控制与传统P I D控制相比,能有效提高活套系统的动态性能和稳定性。
基金Sponsored by National Natural Science Foundation of China(60934007,61174059)Program for New Century Excellent Talents of China(NCET-08-0359)Shanghai Rising-Star Tracking Program of China(11QH1401300)
文摘An innovative sliding mode controller for looper and tension control in hot strip finishing mills was developed based on approximately linearized model. Firstly, a fictitious controller of the reduced order subsystem was designed according to desired dynamics, by which, the angle and tension loops were decoupled on the sliding manifold. Then, a sliding mode controller was used to validate finite time convergence of the state vector to the manifold which guaranteed the stability and performances of the overall system. This solution was considered owing to its well- known robustness and simplicity characteristics concerning disturbances and unmodelled dynamics. Simulation results showed the effectiveness of the proposed controller compared with conventional ones.
