基于改进广义预测算法的精轧宽度控制方法

为了提高热连轧带钢成材率和宽度精度,在精轧末机架后一般配置了测宽仪,利用机架间张力对宽度动态控制,达到调整带钢宽度目的;由于精轧末机架中心线到测宽仪的距离较远,使得系统具有大滞后性及时变性等特点,很难建立精确的数学模型.采用对模型要求宽松的广义预测控制方法,基于广义误差估计值对控制器参数进行自适应调整,直接辨识控制律参数,省略Diophantine方程的求解、矩阵的求逆,缩短在线计算的时间,适用于快速的轧钢过程.仿真结果表明,该方法对精轧宽度这一大时滞、不确定性系统有较好的控制效果.

Width control approach of finishing strip mills based on improved generalized predictive control

In order to increase the rate of qualified products and the precision of strip width in a continuous hot strip mill, a width gauge is usually set behind the last finishing roll stand. The purpose of adjusting strip width can be attained by changing the tension of stands. Since there is a long distance from the last finishing roll stand' s central line to the width gauge, the system is usually a large time-delay and time-variation one; as a result, it is difficult to build an accurate model. An improved generalized predictive control method was proposed which has fewer requirements for modeling and can adaptively adjust the controller's parameters based on generalized estimate errors. The controller's parameters were identified directly without solving the Diophantine equation or the inverse of matrices, and the online computing time was shortened, which makes the approach be very suitable for the fast rolling process. Simulation results showed the method's validity especially for a large time delay and complex system such as width control during finishing rolling.