基于自抗扰控制技术的轧机主传动系统机电振动控制

轧机驱动电机与轧辊间采用长轴连接,连接轴刚度有限,因此在带材高速轧制时,常规电流、转速双闭环控制易产生机电振动和断带现象.为了克服该缺陷,针对轧机主传动系统精确模型不易获得的特点,将不确定外扰和未建模动态视为一个综合扰动项,运用扩张状态观测器对系统状态和综合扰动项进行观测,设计了轧机主传动机电振动扩张状态观测器控制系统;进一步利用自抗扰控制技术设计了一个不依赖于对象模型的轧机主传动机电振动控制系统.仿真研究结果表明:两种控制系统都有效改善了轧机主传动系统的跟踪性能,抑制了系统的机电振动现象,同时对系统内部参数如轧辊转动惯量等的摄动也具有较强的鲁棒性.首次将扩张状态观测器和自抗扰控制技术应用到轧机主传动机电振动控制系统中,并通过与传统电流、转速双PI控制和基于降维状态观测器的状态反馈控制比较,证明了该方法的有效性和优越性.     

基于H∞滤波器和负荷观测器复合补偿的轧机主传动振荡抑制方法

对双环传动的轧机两质量模型进行理论分析并结合工程实际,提出了一种基于H∞滤波器和负荷观测器复合补偿的轧机主传动振动抑制新方法.在负荷观测器系统基础上,通过求解LMI的EVP问题来构造H∞滤波器得到轧辊速度观测值,并据此构造轧辊速度反馈环.较之传统状态观测器和负荷观测器法,该方法放宽了使用观测器的假设条件,将基于负荷观测器和状态观测器的补偿有机结合,实现了电机和轧辊速度的综合振荡抑制.仿真结果表明,与传统负荷观测器方法相比,该方法对电机和轧辊速度同时具有较好的振荡抑制效果.     

1450精轧机组主传动系统扭振测试分析

对1450六机架精轧机组主传动系统扭振进行了现场测试，得出扭振频率及动力放大系数。在理论计算和对现场测试结果进行分析的基础上，提出了预防扭振产生的措施，对控制1450精轧机组主传动系统振动，关事故发生，具有一定的工程实际意义。     

一种改进的遗传算法用于PI控制器的参数寻优

以武钢１７００ｍｍ精轧机主传动系统中控制对象特性参数的改变后系统动态响应品质变差为背景,利用遗传迭代算法双闭环控制系统中转速ＰＩ调节器优化问题,数字仿真结果了该算法的有效性和合理性     

应用负载观测器改善连轧机抗扰性能的研究

本文介绍负载观测器对于改善直流速度控制系统抗扰动态特性的基本理论,提供了它在连轧机生产应用中的成功实例,认为负载观测器值得大力推广。     

离散负载扰动观测器在高速线材连轧机中的应用

为了抑制高速线材连轧机直流调速系统未知外扰负载力矩）对系统造成的不利影响,设计了离散负载扰动观测器及带前馈扰动补偿的直流调速系统,并将重构的负载扰动应用于微张力控制,现场实验表明,所设计的系统有效地改善了调速系统的动,静态性能,改善了微张力控制效果,提高了线材质量。     

自抗扰控制器在气压伺服控制系统中的应用

为提高控制系统的鲁棒性,增强干扰抑制能力,提出了适用于气压伺服系统的自抗扰控制器方案,并讨论了控制参数的整定.自抗扰控制器为非线性控制器,由跟踪微分器、扩张状态观测器和非线性状态误差反馈控制律3部分构成.扩张状态观测器可以实时观测系统状态和扩张状态,从而实现全状态反馈及系统不确定性和外扰的补偿控制.自抗扰控制器的设计不依赖于被控系统的精确数学模型,并对内外扰有较强的抑制能力,在整个系统工作区间都有良好的鲁棒性.仿真结果表明,自抗扰控制器对气动伺服系统模型的不确定性以及外干扰的鲁棒性较好,且具有较优的动态性能.     

重型电动轮自卸车自抗扰传动控制

分析了电动轮自卸车传动控制系统的特点,提出了电动轮自卸车自抗扰传动控制,设计了基于遗传算法参数整定的自抗扰传动控制系统.仿真结果表明,自抗扰控制器完全能够满足系统控制要求,且比同样采用遗传算法参数整定的PID控制具有更强的抗扰能力和鲁棒性.     

全阶转速和扰动观测器在调速系统中的应用

本文提出了重构直流调速系统常值未知外扰和电动机转速的二种全阶观测器。它包括采用和不采用测速发电机二种方案,用以重构转速n扰动量M_f。调速系统采用线性二次型指标状态反馈(LQSF),它与重构信号组成复合控制系统,补偿了负载扰动,降低了动态速降,实现了无超调和无静差。实验表明,这二种观测器方案在工业上有应用价值。     

基于外扰观测器的双通道航天器姿态控制方法

该文提出一种基于外扰状态观测器的航天器姿态控制方法。该方法基于航天器姿态控制模型的线性形式,利用双通道控制原理,分别设计镇定补偿器和伺服补偿器解决恒值调节和随动跟踪问题,通过状态反馈实现极点配置,使系统满足给定的动态和静态指标,同时用外扰状态观测器获取干扰量估计并通过补偿通道对干扰进行抑制和消除。仿真结果表明:该系统具有良好的静态和动态特性,同时具有较强的抗干扰能力和一定的工程应用价值。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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