【作者】 张欣；

【导师】 张殿华；

【作者基本信息】 东北大学 ， 材料加工工程， 2014， 博士

【摘要】 大型薄板酸洗冷连轧成套设备是冷轧生产中系统性极强、技术难度极大、精度要求极高的综合性技术,其核心设备与核心技术的自主集成是我国先进冶金成套设备自主化重要目标之一。本文以某1450mm酸洗冷连轧机组建设及自动化控制系统研发项目为背景,对冷连轧轧制特性与轧制过程中的辊缝控制技术、厚度控制技术、张力控制技术和主令控制技术等进行了研究,并将研究成果应用于生产,取得了良好的控制效果。主要研究内容如下：(1)分析了冷连轧生产过程中轧制变形区及其主要参数的概念以及变形区主要参数的计算方法,为简化微分方程求解问题,研究了采用数值积分方法求解轧制过程工艺参数,给出了适于在线应用的轧制力模型、变形抗力模型、摩擦系数模型及前滑模型。研究了冷连轧过程基本方程,包括秒流量方程、轧机弹跳方程、张力方程及功率方程。(2)结合轧制过程基本方程,建立用于轧制过程特性分析的增量模型,根据求导法则,逐个计算轧制力、轧制力矩和前滑对轧机入、出口厚度以及前后张力的偏微分系数,通过运用矩阵运算方式计算轧制工艺参数间的影响系数。研究了冷连轧过程中厚度与张力的协同优化控制,给出了针对线性二次型问题最优解转化为求解代数Riccati方程之特解的方法,通过仿真分析了来料厚度波动对各机架出口厚度和机架间张力的影响。(3)根据产品厚度精度要求和特殊仪表配置,开发了一套冷连轧机厚度控制系统与张力控制系统。针对实测信号的干扰问题,提出了一种基于双线性变换设计带阻滤波器的方法,在不影响测量信号动态响应的基础上,提高了实测数据的准确性。研究了液压辊缝控制系统的两种控制方式,给出了前馈AGC、秒流量AGC和基于Smith预估器的监控AGC的控制原理与控制算法,设计了用于轧机入、出口张力控制的间接恒张力控制策略,为了保证钢卷内紧外松对张力的要求,给出了锥度张力的设定方法,针对冷连轧过程对机架间张力控制精度的要求,开发了常规张力控制与安全张力控制两种控制策略。(4)针对冷连轧过程的特点和实际情况,设计并建立了一套冷连轧机主令控制系统,开发了轧机速度控制技术,并对其中的预设定值处理、主令速度计算、轧区带钢跟踪及带尾自动定位技术进行了深入的研究。针对轧机出口飞剪和卷取机两个关键设备,优化改进了控制算法和控制结构,实现了稳定高效的自动剪切与自动卷取。结合现场实际情况,采用“逆流调节”的方法实现了轧制过程中的动态变规格。(5)给出了冷连轧机自动控制系统的硬件网络配置和软件结构,针对控制系统设计过程中的几个关键问题进行了介绍,采用现场实际曲线分析了辊缝控制技术、厚度控制技术和张力控制技术的控制效果,对控制系统的效果作出了有说服力的评价。本文的研究结果针对冷连轧过程中的厚度控制、张力控制和主令控制,具有较强的实用性。目前,已将这些控制策略成功应用于某大型薄板五机架冷连轧生产机组,对我国冷连轧控制水平的提高具有积极的促进作用。更多还原

【Abstract】 Complete equipment of large pickling and tandem cold mill is comprehensive technology possessing a strong systemic, great technical difficulty and high precision requirements in cold rolling production. And independent integration of core equipment and technology is one of the important goals about independent production of advanced metallurgical equipment. Based on building and automatic control system development project for 1450mm pickling and tandem cold mill, the study was carried out on rolling characteristics, hydraulic gap control, automatic gauge control, automatic tension control and mill master control and so on. The research results were applied to practical production, which had good performance. The main work is as follows:(1) The composition and parameter calculation method of deformation zone in tandem cold rolling process were analyzed. In order to simplify solving differential equations, solving the rolling process parameters by numerical integration method was studied. The rolling force model, deformation resistance model, friction coefficient model and forward slip model were given, and the basic equations for strip rolling process were studied including mass flow equation, mill spring equation, tension equation and power equation.(2) Taking basic equations for rolling process into account, the incremental models of the rolling process characteristics analysis were established. According to the law of derivation, partial differential coefficients of rolling force, rolling torque and forward slip were individually calculated. And the influence coefficients of rolling process parameters were calculated through the use of matrix operations. Collaborative optimization control of thickness and tension was studied, and the riccati equation method of linear quadratic optimal solution was given. The effect of thickness and tension from raw material thickness fluctuation was studied by simulation.(3) Depending on the product thickness accuracy requirements and special instrument configuration, a set of automatic gauge control system and automatic tension control system for strip cold rolling was designed and established. In order to eliminate the signal interference, a new method for designing the band filter based on the bilinear transformation was developed. Two control methods for hydraulic gap control system were studied. Control theory and algorithms of feed forward AGC, mass flow AGC and monitor AGC based on smith predictor were given. The indirect tension control strategy was designed to control tension for the mill entrance and export. In order to ensure stable export coiling tension, the setting method of taper tension was given. And normal tension control and safe tension control were developed for inter-stand tension control.(4) Taking tandem cold rolling characteristics and actual situation into account, a set of mill master control system for strip cold rolling was designed and established. The speed control technology was studied especially preset value processing, master speed calculation, strip tracking and strip tail positioning. Control algorithms and structures of flying shear and coiler were improved to achieve a stable automatic cutting and coiling. Combined with actual situation, countercurrent adjustment method was used to achieve flying gauge change.(5) The hardware network configuration and software architecture of automatic control system for tandem cold mill were given. Several key issues were elaborated about control system design. The control results of hydraulic gap control, automatic gauge control and automatic tension control were analyzed using actual curves. A convincible evaluation for the control system was made.The results of the study are practical for thickness control, tension control and mill master control of tandem cold mill. The automatic control system has been applied successfully in 5-stand tandem cold mill of a certain cold mill plant. It is benefit to the computer control level of tandem cold mill in China.更多还原