增量式PID控制在温控系统中的应用

温度的控制在科学实验和工业过程中极为普遍,具有典型的意义,而温控系统通常是时变的、非线性的、具有纯滞后的复杂大惯性系统,控制效果与采用的控制算法有很大的关系.针对这一问题,在温度控制实验系统中,设计了一种增量式PID控制算法实现了对温度的控制.通过实验表明,该算法的控制效果要优于传统的PID控制算法,对于工程实际应用具有较强的借鉴作用.     

基于ARM7的实验台温度控制系统实验设计

介绍一种基于ARM7微控制器S3C44BOX的水温温度控制系统实验。阐述了实验系统的硬件构成和软件设计。系统硬件由测温单元、控制单元、键盘显示单元以及传送单元组成，并给出了硬件原理图。针对被控对象存在的大惯性、纯滞后的特点，设计出一种基于偏差的多段式PID控制算法。     

四路智能温度测控仪

本文介绍一种采用8031芯片的单片机四路温度测控仪,这种仪表具有智能化、通用性强和使用方便等优点。文中提出了一种提高8位A/D转换器分辨率的方案,并利用PN结的温度特性实现热电偶冷端温度补偿,采用参数自整定模糊控制算法解决大滞后对象的温度控制。仿真结果表明,这种控制算法具有较好的控制效果。     

大型游泳池水温的预测模糊控制

分析了容积为 2 50 0m3大型游泳池的池水温度特性 ,提出了预测模糊控制算法 .采用该算法对具有大惯性、纯滞后等特性的池水温度进行控制 ,取得了良好的效果 ,而且调节过程平稳 ,实际控制精度达± 0 .0 2℃ .由此可得 ,这种算法也可以应用到具有类似特性参数的工业过程控制之中 ,并能取得有效的控制精确度和稳定性 .     

模糊控制器在温度控制系统中的应用

针对温度控制系统被控对象中普遍存在的大惯性、纯滞后的实际情况,采用把模糊控制与PID控制方式相结合的控制策略,设计了温度模糊控制系统.同时,设计时考虑到温度控制系统升温时一般温度偏差负值较小,因此模糊控制器误差的论域采用了正负不对称取法,以简化控制规则和控制器.仿真与实验结果表明,该控制方法很好地改善了系统的动态特性,提高了稳态精度.     

大时滞过程的神经元Smith预估控制器的设计

给出一种神经元Smith预估控制器方案,用于大时滞过程控制。新算法采用专家经验实现神经元PID的变增益控制,改善神经元控制品质。通过对一阶惯性加纯滞后的典型工业对象的仿真研究,表明这种控制方式具有良好的适应性与鲁棒性。     

基于继电器反馈的一种建模法

基于继电反馈的PID参数自整定技术有效地克服了人工整定的缺陷, 具有算法简单、控制温度范围大等优点。本文在继电型自整定PID控制策略基本思想基础上,通过分析一阶惯性加纯滞后控制对象在继电特性作用下的输入输出特性,提出一种基于继电器反馈的建模方法。该方法为被控对象的自整定参数设置提供了重要依据。选定被控对象,通过仿真验证了该方法的有效性。     

连续排液式自动平衡头的自适应模糊PID控制算法研究

针对持续注液平衡头系统控制对象的大惯性、非线性、纯滞后等特性,设计了一种改进的模糊PID控制器所设计的控制系统比常规PID控制系统具有较强鲁棒性,系统具有良好的适应能力,其有很好的快速性和很小的超调。     

基于PWM技术的电加热系统控制算法研究

针对电热管加热类负载的控制特点，就数学模型的建立、高精度控制算法的确定、PWM控制方法的实现等问题进行了详细的分析和论证，总结出一种对于一阶惯性环节加纯滞后类对象如何确定最优控制算法的分析方法。     

纯滞后系统的灰色预测控制

本文针对具有纯滞后的系统的控制,采用了一种基于 GM(1,1)模型的灰色预测控制算法。这种新型控制器的主要优点是不需要掌握关于被控对象模型结构的先验信息,并具有计算简单、自适应性强等特点,是一种通用控制器。数值仿真及结果对比验证了该算法的有效性。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has