板带轧机板形控制倾辊弯辊神经模糊PID模型

板形是板带轧制的重要质量指标,倾辊和弯辊是板形控制的重要手段.目前常规的PID控制算法被广泛应用到板带轧机倾辊和弯辊板形控制系统中,但由于实际系统随机干扰严重,具有多变量、非线性、强耦合的特征,难以建立较为准确的数学模型,常规的PID控制算法很难满足板形高精度控制的要求.为能提高倾辊和弯辊板形控制系统的性能,在常规PID控制算法的基础上,建立基于神经网络的模糊PID倾辊弯辊板形控制模型,通过神经网络的自学习能力和模糊控制的"概念"抽象能力的有机结合寻找一个最佳的P、I、D非线性组合控制律,增强对控制环境变化的适应能力和自学习能力.仿真试验结果表明,该模型能很好地跟踪板形的目标设定值,响应快,超调小,鲁棒性强,可提高倾辊和弯辊对板形的控制精度,为板形高精度控制提供了一种新方法.     

万能凸度轧机中间辊偏移板形调控能力分析

1420单机架万能凸度轧机(Universal crown mill,UCM)轧制极薄带时,中间辊偏移对正向轧制与负向轧制时工作辊弯辊、中间辊弯辊及中间辊窜辊的板形调控特性存在一定的影响,从力学角度分析辊系的受力状态,并运用LS-DYNA有限元软件建立显示动力学模型,定量计算中间辊不偏移轧制与正向偏移轧制及负向轧制时各板形调控手段的调控特性。计算结果显示轧机中间辊不偏移时,工作辊弯辊力与带钢凸度呈线性关系,随着工作辊弯辊力的增大,带钢凸度减小;当中间辊偏移时,工作辊弯辊调控功效要大于中间辊不偏移时,且正向轧制的弯辊调控功效要优于负向轧制;中间辊弯辊调控特性表现出与工作辊弯辊相似的变化趋势。不同中间辊窜辊的板形调控能力变化不大,不偏移轧制与负向轧制调控能力基本相同,正向轧制在窜辊量为15~30 mm范围内,其调控能力好于另外两种轧制工况。     

HC轧机平直度调节手段对各次平直度分量的影响规律研究

现代轧机一般配备多种平直度调节手段,各种调节手段之间存在着一定的耦合关系,为分析各种平直度调节手段对各次平直度分量的影响规律,采用分割模型影响函数法和条元变分法建立HC轧机的平直度计算模型,利用该模型计算倾辊、工作辊弯辊、工作辊非对称弯辊和中间辊横移4种调节手段对1次、2次、3次和4次平直度分量的影响系数,分析发现,倾辊和工作辊非对称弯辊对平直度的影响规律类似,主要影响1次和3次平直度分量,并且对1次分量的影响程度要大于对3次分量的影响程度;工作辊弯辊和中间辊横移主要影响2次和4次平直度分量,并且对2次分量的影响程度要大于对4次分量的影响程度,该结果系统地揭示各种调节手段对各次平直度分量的影响规律,为平直度在线控制模型的建立、实现提供理论基础。     

Coupled dynamic modeling of rolls model and metal model for four high mill based on strip crown control

The crown is a key quality index of strip and plate,the rolling mill system is a complex nonlinear system,the strip qualities are directly affected by the dynamic characteristics of the rolling mil.At present,the studies about the dynamic modeling of the rolling mill system mainly focus on the dynamic simulation for the strip thickness control system,the dynamic characteristics of the strip along the width direction and that of the rolls along axial direction are not considered.In order to study the dynamic changes of strip crown in the rolling process,the dynamic simulation model based on strip crown control is established.The work roll and backup roll are considered as elastic continuous bodies and the work roll and backup roll are joined by a Winkler elastic layer.The rolls are considered as double freely supported beams.The change rate of roll gap is taken into consideration in the metal deformation,based on the principle of dynamic conservation of material flow,the two dimensional dynamic model of metal is established.The model of metal deformation provides exciting force for the rolls dynamic model,and the rolls dynamic model and metal deformation model couple together.Then,based on the two models,the dynamic model of rolling mill system based on strip crown control is established.The Newmark-β method is used to solve the problem,and the dynamic changes of these parameters are obtained as follows:(1) The bending of work roll and backup roll changes with time;(2) The strip crown changes with time;(3) The distribution of rolling force changes with time.Take some cold tandem rolling mill as subject investigated,simulation results and the comparisons with experimental results show that the dynamic model built is rational and correct.The proposed research provides effective theory for optimization of device and technological parameters and development of new technology,plays an important role to improve the strip control precision and strip shape quality.     

带钢冷轧闭环反馈控制最优化算法程序开发

基于多变量最优化控制的带钢闭环反馈控制模型能够充分利用弯辊和轧辊倾斜等平直度控制机构对板形偏差进行控制。闭环反馈控制的目的是使带钢实测板形与目标板形一致,闭环反馈最优化算法程序能充分利用输入信息,全面考虑多个执行机构对板形的作用,避免各控制之间的相互影响,它是该模型准确计算板形调节量的关键。为了实现自主建立带钢冷轧生产线,对某厂1 700 mm四机架四辊冷连轧机第四机架闭环反馈控制进行深入研究,根据对偶法采用C语言开发出基于多变量最优化闭环反馈计算程序并将其嵌入到可编程逻辑控制器(Programmable logic controller,PLC)中,开发出自主的基于多变量最优化闭环反馈控制模块。由该模块计算的闭环反馈平直度执行机构调节量与采用Matlab工具箱Quadprog函数计算结果一致,计算精度高。     

1200WS轧机结构参数设计

WS轧机是目前生产优质板材产品较为理想的先进设备之一,它采用了一个工作辊可移动和工作辊弯辊技术,可以有效的改善和提高板形精度.通过对设计方案的选择,力能参数及其它重要参数的计算,使轧机生产出来的产品达到了国家标准和设计要求.并且同时进行了结构设计和轧辊零件的设计,使结构更加合理,并且突出了WS四辊可逆式冷轧机的作用     

Study on the improved accuracy of strip profile using numerical formula model in continuous cold rolling with 6-high mill

The quality requirements for thickness accuracy in cold rolling continue to become more stringent. In cold rolling mill, it is very important that the rolling force calculation considers rolling conditions. The rolled strip thickness was predicted using calculated rolling force. However, the prediction of strip thickness in cold rolling is very difficult; in particular, for 6-high mill with shifted intermediate roll (IMR), the accuracy of thickness is not good. In this study, to improve the accuracy of rolled strip thickness, the roll gap flattening can be given based on Hertz contact theory, with contact between rolls and the smooth cylindrical rolls for the rolling elastic deformation. Also, the distribution of the roll gap flattening may be calculated using the contact force of unit transverse length. The strip profile at the continuous cold rolling is calculated by using the numerical analysis model considering the initial strip profile before cold rolling. Hence, we propose that the numerical model can predict the rolled strip profile more quickly and accurately and be applicable to the field. The results of the proposed numerical model were verified by FE-simulation and cold rolling experiments of 6-high mill with five stands.     

小型四辊轧机工作辊水平位移对板形的影响

小型四辊轧机由于工作辊长径比较大且辊径较小而造成工作辊沿轧制方向很容易出现水平位移现象,常规四辊轧机板形计算模型不能满足出口板形的准确计算与预测,为此,充分结合小型四辊轧机的设备与工艺特点,建立了四辊轧机考虑工作辊水平位移时的板形模型;通过板形对比说明了该模型计算结果的准确性。在此基础上,具体分析了工作辊水平位移产生的规律以及在考虑工作辊水平位移时弯辊力对板形控制的影响,并将该模型应用到某钢厂650可逆四辊轧机机组,开发了650可逆四辊轧机工作辊水平位移对板形影响分析软件,有效地解决了以往板形计算误差大的问题,实现了对出口板形的准确计算与预测,大大提高了板形控制精度。     

新型四辊冷轧机工作辊双向移动技术

新型四辊冷轧机工作辊双向移动技术极大地提高了板形控制能力，降低了板带轧制过程中产生的边降，延长了轧辊使用周期，可广泛应用于板带轧制。     

小辊径冷轧机组压扁系数模型及其影响因素

针对工作辊“长径比”大且辊径绝对值小的轧机在轧制过程中,工作辊产生较大水平挠曲的问题,在考虑设备与工艺特点的基础上,研究了工作辊发生水平挠曲时的载荷分布情况,推导了新的辊间压扁系数模型,并以典型规格产品为例,定量分析了工作辊出现水平挠曲时,单一影响因素变化对辊间压扁系数的影响。为了验证模型,在完成相关理论分析的基础上,编写了预报软件,并给出了现场实验结果。     

Flatness Control Based on Dynamic Effective Matrix for Cold Strip Mills

Steel strips are the main of steel products and flatness is an important quality indicator of steel strips. FLatness control is the key and highly difficult technique of strip mills. The boule-neck restricting the improvement of flatness control techniques is that the research on flatness theories and control mathematic models is not in accordance with the requirement of technique developments. To build a simple, rapid and accurate explicit formulation control model has become an urgent need for the development of flatness control technique. This paper puts forward the conception of dynamic effective matrix based on the effective matrix method for flatness control proposed by the authors under the consideration of the influence of the change of parameters in rolling processes on the effective matrix, and the concept is validated by industrial productions. Three methods of the effective matrix generation are induced: the calculation method based on the flatness prediction model; the calcuLation method based on the data excavation in rolling processes and the direct calculation method based on the network model. A fuzzy neural network effective matrix model is built based on the clusters, and then the network structure is optimized and the high-speed-calculation problem of the dynamic effective matrix is solved. The flatness control scheme for cold strip mills is proposed based on the dynamic effective matrix. On stand 5 of the 1 220 mm five-stand 4-high cold strip tandem miU, the industrial experiment with the control methods of tilting roll and bending roll is done by the control scheme of the static effective matrix and the dynamic effective matrix, respectively. The experiment result proves that the control effect of the dynamic effective matrix is much better than that of the static effective matrix. This paper proposes a new idea and method for the dynamic flatness control in the rolling processes of cold snip mills and develops the theory and model of the flatness control effective matrix method.     

辊间压力分布影响因素的研究

四辊轧机辊间压力的分布将直接影响轧机负载辊缝形状,轧辊磨损情况以及轧辊强度的准确校核。本文采用分割单元法,研究了轧件宽度,轧辊直径,弯辊力,轧辊辊型,轧制压力分布等诸多因素对辊间压力分布的影响,给出了辊间压力分布规律,理论计算值与实测数据吻合较好,研究结果对于板形凸度计算及轧机设计有一定的借鉴作用。     

Shape control of alloy steel rolled by sendzimir mill

In order to improve quarter waves occurred in the wide and thin gauged alloy steel rolled by 20-high sendzimir mill, a computer simulation based on the divided element method and an actual cold rolling experiment were carried out. Quarter waves were simulated by elastic deformation analysis of rolls considering bending deformation of back up rolls and the effect of control actuators on controllability of quarter waves were analyzed. Computer simulation showed that control actuators such as shifting of the 1st intermediate roll and crown adjustment of As-U-Roll in back up rolls were not effective to control quarter waves and that changing taper mode (both length and magnitude) at the barrel-end taper radius of the 1st intermediate roll was rather very effective. From an actual rolling experiment it was verified that quarter waves could be reduced remarkerably by changing taper mode of the 1st intermediate roll.     

LVC工作辊在超宽带钢热轧机的应用

分析了超宽带钢轧机的板形控制特性,指出其在板形控制方面的不足.为增加超宽带钢热轧机的板形调节能力,开发了线性变凸度(LVC)工作辊,实现板形调节与带钢宽度成线性关系,其板形控制性能优于CVC技术.建立了LVC工作辊的板形控制策略模型,在超宽带钢热轧机上实现了长期稳定应用.生产实绩表明,LVC工作辊可显著提高带钢的凸度控制精度,对凸度控制要求严的供冷轧料和凸度难控制的高强度管线钢,其凸度控制在50±18mm的比例可达96%以上.     

六辊CVC宽带轧机轧辊接触压力横向分布特性的计算机仿真

用条元法分析带材的三维塑性变形,用影响系数法分析辊系的弹性变形,将二者联立,对1850mm六辊CVC轧机冷轧带材轧辊接触压力的横向分布进行了计算机仿真。结果表明,CVC中间辊横向移动、工作辊弯和中间辊弯辊等手段,对轧制压力的横向分布影响很大,对辊间压力的横向分布也有明显影响。在各种情况下,辊间压力都呈S形分布。     

PROFILE AND FLATNESS CONTROL SYSTEM IN 1 700 mm HOT STRIP MILLS OF ANSTEEL

Varying contact-length backup roll and linearly variable crown work roll are provided for improving the mill performance of profile and flatness control. Integrated with theses technologies, relevant profile and flatness control models are developed for hot strip mills on the basis of large amount of finite element calculation. These models include shape setup control model in process control system, bending force feedforward control model, crown feedback control model and flatness feedback control model in basis automation system. Such a profile and flatness control system with full functions is applied in 1 700 mm industrial hot strip mills of Ansteel. Large amount of production data shows that the crown precision with the tolerance of±18 μm is over 90%, the strip percentage which the actual flatness is within ±25 I-unit surpasses 96%, and general roll consume is reduced by 28% by using the profile and fiatness control system. In addition, schedule-free rolling is realized.     

热带钢轧机线性变凸度工作辊的研制及应用

为改善轧机的板形调控性能,在分析连续变凸度(Continuously variable crown,CVC)辊形技术的板形控制特性的基础上,开发出用于热带钢轧机的线性变凸度(Linearly variable crown,LVC)工作辊辊形技术及其相应的板形控制模型。LVC技术的板形调节能力与窜辊量成线性关系,同时与带钢宽度成近似线性关系。在满足宽带钢板形控制要求的同时,提高轧机对窄带钢的板形控制能力,使轧制各种规格带钢时所需弯辊力处于合理的的幅值。在1 700 mm热带钢轧机上一年多的工业应用表明,采用LVC工作辊后,板形控制精度提高30%以上,尤其是轧制高强度钢种时,凸度下降显著,轧制公里数一般都大于55 km,磨损辊形和轧辊消耗与常规工作辊基本一致。     

20辊轧机轧件截面形状与边部减薄预报软件开发

利用接触元双坐标法（CEM）建立了双AS—U—Roll系统森吉米尔轧机轧制过程中轧件及辊系变形行为的CEM函数矩阵,并开发了SM4SM软件。该软件能够很好地预报各种轧制条件下轧件截面形状、轧件边部减薄、轧制力、轧辊挠曲等功能。文中应用SM4SM,分析了第一中间辊锥角、锥度长度和窜辊长度对轧件截面形状和轧件边部减薄控制的影响。研究结果对冷轧过程控制轧件板形和边部减薄具有重要的参考价值。     

An innovative development of a four-high foil rolling mill

During foil or ultrathin strip rolling, elastic deflection variation of the work rolls at the contact surface with the strip causes non-uniform thickness distribution of the product in the width direction, which possibly causes a central wrinkling or an edge fracture on the product. This study developed a four-high prototype rolling mill, comprising two work rolls fabricated from an ultrastrength alloy. This prototype rolling mill was composed of a housing frame set, a roll set, a roll gap adjusting mechanism, and a power transmission system. The finite element analysis was used for determining the frame dimensions and work roll diameters. Several experimental rolling passes of stainless steel strips were conducted using this self-developed prototype rolling mill to achieve a 0.05-mm-thick foil product.     

四辊CVC热带钢轧机板形控制特性的仿真

用流面条元法分析带材的三维塑性变形．用影响系数法分析辊系的弹性变形，将两者耦合，建立了四辊轧机板形和板凸度的分析计算模型。对四辊CVC热带钢轧机板形控制特性的仿真表明，随着CVC工作辊横移距离的增加，前张应力沿横向的差距增大；随着工作辊弯辊力的增加，前张应力沿横向的差距增大，且变化主要集中在板宽的边部；随着板宽的增加，前张应力沿横向的差距先减小后增大。