连续退火机组SF段带钢跑偏混合动态监测模型

针对宝钢1 220 mm连续退火机组均热炉(SF)段带钢经常发生跑偏或打滑的问题,提出了一个基于最小二乘支持向量机(LSSVM)的带钢跑偏分类模型。使用改进粒子群算法对其模型参数进行寻优,再将LSSVM分类模型与主元分析(PCA)方法相结合;并基于动态时间窗思想,提出了一个SF段带钢跑偏的混合动态监测模型,开发了SF段带钢跑偏监测系统。基于实际生产数据的仿真结果表明,所提出的LSSVM模型具有较高的分类精度;相较于单一方法,混合监测模型能够更加准确地对带钢跑偏进行分析和预警。     

带式输送机输送带跑偏原因分析及处理方法

针对带式输送机输送带常见的几种跑偏规律,即哪偏往哪跑、哪高往哪跑、哪松往哪跑,详细分析了引起这几种跑偏现象的主要原因,提出了相应的调整方法和预防措施。     

连续退火机组跳动辊区域带钢张力的建模及仿真

以连续退火机组跳动辊区域的带钢张力为研究对象,建立了带钢张力的机理模型和状态空间表达式,克服了现有张力模型中的2个缺点.根据现场的控制系统,开发了控制仿真程序,并建立了由张力模型仿真程序和控制仿真程序所组成的带钢张力闭环控制仿真软件.仿真实验表明,所开发的仿真软件能够及时、准确地反映带钢张力的稳态和动态特性.     

连续退火机组张紧辊带钢张力的建模及解耦控制

在带钢连续退火机组中,张紧辊区域的带钢张力直接影响着机组的运行速度以及带钢质量,因此,张紧辊区域的带钢张力是连续退火机组中的关键被控变量.本文首先建立了张紧辊区域带钢张力的动态机理模型和状态空间模型,并针对张紧辊带钢张力系统的多变量、强耦合等特性,采用极点配置和动态解耦算法,提出了带钢张力的多变量解耦控制器.仿真实验结果表明,所提出的解耦控制器实现了多个带钢张力控制回路之间的动态解耦,并可获得良好的控制效果.     

连续微段前瞻及加减速算法

针对目前实时曲线重构微段加工方法存在的不能准确重建设计轮廓、重构曲线的轮廓误差大于轮廓误差允许值的问题,在前瞻算法中新建了曲线轮廓重构条件,其中包括基于转角允许通过速度的转角条件和基于连续转角与段长相关变化的段长条件,同时提出了基于节点的S型加减速速度规划算法.在应用该算法进行的仿真与实验中,重构曲线与微段间的最大轮廓误差小于原曲线在CAM软件中生成微段时所设定的允许轮廓误差,且加工效率是传统微段加工过程的1.5～3.3倍.实验结果表明,采用文中算法可以从NC代码中有效地区分出原设计轮廓中的几何元素,找到轮廓上的基点,从而能准确地还原零件的设计轮廓,并使插补点精确地通过每个重构段的段内节点,在提高了加工效率的同时保证了加工精度.该项研究结果可应用于中高档数控系统设计及复杂曲面的加工中,以提高加工效率.     

连续退火机组张紧辊带钢张力的多变量建模及跟踪控制

通过对带钢张力产生机理的分析,建立了张紧辊带钢张力的动态机理模型和状态空间模型,在此基础上,与传统的带钢张力比例—积分—微分(PID)控制方法不同,采用状态反馈和极点配置方法设计了带钢张力的多变量跟踪控制器.所设计的带钢张力跟踪控制器能够使各个带钢张力的实际值渐近跟踪相应的设定值,可获得良好的控制效果.通过仿真实验证明了本文的带钢张力模型和跟踪控制方法的有效性.     

T-MPLS网络互通问题分析及解决方案

随着数据流量的不断增长及其高突发性,基于SDH技术的传送网逐渐显示出不可解决的劣势.下一代传送网将被基于分组的传送技术所垄断,T-MPLS是一种新的基于分组传送的技术,目前T-MPLS主要定位在城域传送网络,并逐渐向核心网络部分进行扩张.本文基于ITU-T所定义的T-MPLS框架体系结构,结合已有的基于MPLS技术的组网方式,分析了T-MPLS未来的应用前景,并给出了未来传送网络可行的演进模型.     

伽利略E5段信号结构分析及仿真

本文介绍了伽利略卫星导航系统E5段的信号结构,新型调制方式BOC的基本原理和在E5中的应用,并对伽利略E5信号的结构作了分析和简化,验证了E5段的Alt BOC信号在接收端可以近似为一个QPSK信号,最后给出了对于Alt BOC信号的接收和捕获的Matlab仿真结果。     

浅谈高校校园网安全问题分析及解决方案

校园网是高校信息发布和管理的重要平台,必须建立高效的、智能化的网络安全防范体系以保护校园信息和关键应用的安全.然而,随着校园网规模的不断扩大以及应用的不断深入,校园网中的安全问题也逐步显现出来.投入运行后,又疏于安全管理,以致校园网没有完全发挥它应有的作用.因此,只有正确分析和解决校园网运行中出现的问题,建立安全可靠的运行机制,才能保证校园网的正常运行.     

关于复制卡问题的分析及解决方案

目前市场上出现了可以时SIM卡进行复制的设备,该设备被不法分子利用,对运营商及正常用户造成了极其恶劣的影响.本文通过对复制卡情况的跟踪,详细阐述了复制卡出现的原理和机制,并根据分析结果对该现象提出了相应的解决方案.     

限定记忆法辨识带钢热镀锌退火炉模型参数

最小二乘参数估计方法可用于线性的或非线性的系统参数辨识,包括动态的、静态的和参数的或非参数的模型辨识,其递推算法更是收敛可靠,简单实用。但是随着数据的不断增长,最小二乘的递推算法将失去修正能力,出现数据饱和现象,限定记忆最小二乘法解决了这一问题,并能得到无偏、一致、有效估计。以已建立的连续带钢热镀锌退火炉数学模型为实例,用限定记忆最小二乘法辨识连续带钢热镀锌退火炉模型参数。通过对限定记忆最小二乘法的研究,进行模型参数辨识,并给出辨识结果和分析,结果证明了该方法的优越性。     

冷轧带钢连续热镀锌机组自动化系统

带钢连续镀锌机组自动化系统庞大、复杂、IO点数超过1万点,PLC和HMI系统内部变量达数十万个,通过现场总线连接的变频调速装置超过200台,机组速度、张力等被控量要求精度高、反应快。机电一体品种多,接口多。在自动化系统的设计、成套、调试中均需考虑各种技术问题。本文以某机组为例,介绍了一种较为全面的解决方法。     

冷轧带钢连续退火机组电气传动系统

带钢连续退火机组用电设备数量大、种类多,既有需要调压调频（VVVF）的变频风机,需要矢量控制（VCT）的开卷机、卷取机、张力辊、活套,也有需要交流晶闸管调压调温的电辐射管,需要直流低电压大、电流的电解清洗装置。在电气传动系统的设计、成套中均需考虑各种技术问题。本文以某机组为例,介绍了一种较为全面的解决方法。     

宝钢正硅酸钠清洗液的智能控制

根据宝钢ＣＭ１２机组正硅酸钠清洗系统的需要，设计了模糊和ＰＩＤ相结合的复合控制器，进行了系统分析、理论建模和仿真实验。记系统由于溶液重复使用，具有自身特有的大惯性和大滞后，且有一定的时变性。实际应用表明这种方法控制效果良好。     

带钢磁悬浮防抖系统的研究

在镀锌生产线中垂直带钢水平晃动会造成镀层不均。基于磁悬浮技术能够实现无接触稳定的特点,研制了用于带钢防抖的磁悬浮系统。分析建立了系统的数学模型,设计了PID控制器。研究设计了包括传感器、控制器、功率放大器的磁悬浮电控系统。在模拟试验台上对系统的性能进行了试验研究。通过试验证明了该磁悬浮系统能够稳定地悬浮带钢,减小带钢在外力扰动下的振幅和回到稳态所需的调节时间,并且在激振试验中成功地使带钢的振幅减小了71.4%。     

Finite element analysis of shape control for continuous hot rolling mills of super wide strip steel

The efficacy of shape control is the core of this technology and the main basis of automatic shape control system model designing.This passage constructs the three-dimensional elastic deformation model of CVC plus roll system in 2250 mm hot rolling mill.Comparing and analyzing different influence of working factors on control characteristic,the shape control characteristic of CVC plus roll system in its whole work time is studied,and the cause is analyzed and the difference of the roll gap curve and crown adjustable area in early and latter work time is compared.The outcome has crucial meaning in both theory and production.     

Characterization of coplanar strip lines on dielectric boards for RF and microwave applications

We report the characterization of coplanar strip (CPS) transmission lines on dielectric boards at millimeter‐wave frequency up to 40 GHz. The CPS line was analyzed and simulated using computer‐aided design tools. Many CPS lines were built on RT/Duroid board and the measured attenuation is as low as 0.8 dB/cm at 30 GHz. CPS lines of various electrode width and width‐to‐gap ratios were measured to obtain key design guidelines. The CPS line has both the signal and ground electrodes on the front surface of the board. In contrast to the microstrip line, the CSP line does not include the backside of the board as a part of the transmission line. Thus, the backside can be left open as dielectric or metallized. The backside condition can affect the wave propagation if it is too close to the electrodes. We simulated and measured the attenuation coefficient, line impedance, and electrical field distributions for different backside conditions. Our results clearly indicate that the CPS line is an attractive transmission line on the board level in millimeter electromagnetic waves applications. Its applications can be extended to microwave and millimeter‐wave integrated circuits. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

板带钢表面质量实时监测体系研究

板带钢市场竞争的日益激烈,传统的检测方法正逐渐退出应用舞台,更稳定高效表的面检测解决方案成为国内外钢铁企业的找寻目标.针对实际应用的需要,从表面缺陷采集系统,缺陷处理和识别系统、质量智能评价与推理系统等3个方面首次系统地阐述了板带钢表面质量实时监测体系,以期推动目前我国板带钢表面缺陷的在线监测研究水平.     

Study on continuous network design problem using simulated annealing and genetic algorithm

In general, a continuous network design problem (CNDP) is formulated as a bi-level program. The objective function at the upper level is defined as the total travel time on the network, plus total investment costs of link capacity expansions. The lower level problem is formulated as a certain traffic assignment model. It is well known that such bi-level program is non-convex and non-differentiable and algorithms for finding global optimal solutions are preferable to be used in solving it. Simulated annealing (SA) and genetic algorithm (GA) are two global methods and can then be used to determine the optimal solution of CNDP. Since application of SA and GA on continuous network design on real transportation network requires solving traffic assignment model many times at each iteration of the algorithm, computation time needed is tremendous. It is important to compare the efficacy of the two methods and choose the more efficient one as reference method in practice. In this paper, the continuous network design problem has been studied using SA and GA on a simulated network. The lower level program is formulated as user equilibrium traffic assignment model and Frank–Wolf method is used to solve it. It is found that when demand is large, SA is more efficient than GA in solving CNDP, and much more computational effort is needed for GA to achieve the same optimal solution as SA. However, when demand is light, GA can reach a more optimal solution at the expense of more computation time. It is also found that increasing the iteration number at each temperature in SA does not necessarily improve solution. The finding in this example is different from [Karoonsoontawong, A., & Waller, S. T. (2006). Dynamic continuous network design problem – Linear bilevel programming and metaheuristic approaches. Network Modeling 2006 Transportation Research Record (1964) (pp. 104–117)]. The reason might be the bi-level model in this example is nonlinear while the bi-level model in their study is linear.