【作者】 孙涛；

【导师】 刘相华； 张殿华；

【作者基本信息】 东北大学 ， 材料加工工程， 2009， 博士

【摘要】 现代工业的发展对中厚板厚度精度不断提出更高的要求,高精度的厚度控制技术一直是轧钢自动化研究的热点。本文以某3000mm中厚板自动化控制系统开发项目为背景,对过程控制设定系统、快速高精度的辊缝控制技术、分段厚度控制技术以及提高厚度控制精度的补偿方法等进行了研究,现场应用取得了良好的效果。主要研究内容和进展如下:(1)分析中厚板生产过程控制中的轧制规程计算及其数学模型,包括轧制策略的选择、分阶段的轧制规程负荷分配计算、负荷计算数学模型及模型自学习。为提高轧线自动化水平,实现全自动轧制,研究并开发了以轧制节奏控制为基础的轧制规程道次自动设定技术。(2)比较变加速度和恒加速度位置控制特征曲线的优缺点,以恒加速度位置控制特征曲线为背景,开发了快速高精度的EGC技术,通过在线参数自适应的方法,对曲线参数进行实时调整和优化,可以使EGC始终保持快速高精度的特性。(3)提出一种动态补偿液压伺服阀零漂的方法,在不降低原HGC系统的动态响应速度的基础上,大幅度提高了HGC系统的控制精度。现场应用表明,采用该技术的HGC系统定位误差可以长期保持在±2μm之内。(4)在使用高精度厚度计模型的基础上,开发了分段厚度控制技术。该技术将轧件沿长度方向分为细小片段,采用高精度厚度计模型,根据实测辊缝和轧制力,分道次逐段计算并存储轧件的厚度和塑性刚度,准确跟踪轧件的厚度波动和塑性刚度变化,对各片段进行单独控制,提高了轧件的同板厚差控制精度。针对变厚度轧制中的楔形段轧制,采用分段厚度控制技术,利用HGC系统位置闭环和压力闭环耦合的特性,研究了楔形段起点自动判断的方法。(5)结合分段厚度控制技术,针对现场应用的特点,研究了利用测厚仪反馈信号进行辊缝零点自学习的方法。(6)针对中厚板轧制中头尾厚度超差的现象,开发了一种新型中厚板头部厚度控制的方法,不但改善头尾厚度超差效果显著,还可以通过调整参数,减小钢板切头部分的厚度,从而提高成材率。本文的研究结果针对高精度的中厚板厚度控制,具有较强的实用性。所开发的控制系统已经成功应用于多套中厚板轧制生产线,为企业创造了很好的经济效益。更多还原

【Abstract】 With the development of modern industry, the demand for plate thickness accuracy is becoming critical. The high-accuracy gauge control technologies are hot issues in rolling automation research. Under the background of automatic control system development project for 3000mm plate mill in a steel company, the study was carried out on preset system of process control, rapid and high-accuracy gap control, piecewise thickness control, compensation methods for improving thickness accuracy and so on. The research results were applied on site successfully, and the precision of thickness were satisfied. The main progress is as follows:(1) The rolling schedule preset models and process data tracking method were analyzed, including rolling strategy selection, rolling schedule computation by load distribution methods, load distribution mathematical models and their self-learning methods. The rolling schedule automatic setting technology was developed for the full automatic rolling control purpose, based on mill pacing control.(2) Comparing the position control characteristic curves with variable and constant accelerated velocity, the merits and drawbacks were pointed out. Rapid and high accuracy EGC technology was developed by on-line parameters adaptive method, based on the characteristic curve with constant accelerated velocity. EGC keeps rapid and high-accuracy characters by real-time adjusting and optimizing the curve’s parameters.(3) A dynamic compensation method for servo valve’s zero drift was developed which improves the positioning accuracy of HGC system without decreasing its dynamic response rate. Applications on site showed that HGC system kept high-accuracy with positioning error in±2μm.(4) Piecewise thickness control technology was put forward based on high-accuracy gaugemeter model. Work piece is divided into thin pieces along the longitudinal direction. The thickness and plastic stiffness of every piece are computed by high-accuracy gaugemeter model with measured gap and rolling force respectively. This technology tracks the thickness and plastic stiffness fluctuation of every piece and controls its thickness. Applications showed that the thickness deviations of same plate were eliminated greatly. The automatic judgement methods for the starting point of thickening and thinning wedge in variable-thickness rolling were developed, adopting piecewise thickness control technology and the coupling characteristic of the position and rolling force closed loop in HGC system.(5) In accordance with the features on site, adopting piecewise thickness control technology, a gap zero point self-learning method was developed by using the measurement signal from gauge meter.(6) In order to eliminate the oversize thickness at the plate head and tail, a new gauge control method for plate head was developed, which has good performance on site. The crop of cutting head was reduced greatly, by adjusting the parameters. It is benefit to finishing yield.The results of the study are practical for high-accuracy thickness control of plate mill. The automatic control system has been applied successfully in many plate mill lines which has achieved great economic results.更多还原