模糊PID控制在液位控制系统中的应用

提出一种基于模糊规则的PID控制器的设计方法.该方法以建立模糊规则和进行模糊推理来调整PID控制器的kp,ki,kd等参数,通过JX-300X集散控制系统对QXLPC-Ⅲ液位对象进行控制.实验结果表明,所设计的模糊PID控制系统比常规PID控制系统具有更优良的控制品质.     

多级思维进化寻优的模糊PID控制器设计

为了提高模糊PID控制器的适应性，首先对模糊PID控制器进行简化处理，简化后的PID被控参数与量化因子、比例因子和解析规则相结合，构成多参数寻优的模糊PID控制器，同时采用多级“思维进化算法“对参数进行分组分阶段交替寻优，以适应各种环境的变化。仿真结果表明，MEA—模糊PID控制系统的结构合理，解决了模糊控制中参数优化问题，取得了良好的控制效果；同时在保证控制效果的情况下，大大简化了模糊PID控制器的设计。     

一类基于PID控制的新型模糊控制方法

研究了一类基于模糊规则的变参数 PID控制方法 .对于模型未知对象 ,常规 PID控制器参数的调节一般要基于一些语言信息的经验知识 ,这对 PID参数的调节带来一定的困难 .模糊控制在处理语言信息方面具有一定的优势 ,因此将模糊控制和 PID控制方法相结合组成一种复合控制器的设计是可行的 .采用 TS模糊模型 ,给出了一类给予模糊规则的变参数 PID控制器的设计 .这种控制方法兼备模糊控制与 PID控制优点 ,具有广泛的应用价值     

磁悬浮系统的模糊PID控制器设计

基于GML1001磁悬浮实验装置设计了一个模糊PID控制器.该控制器利用传统的PID控制器和模糊控制器相结合形成,能根据系统偏差的大小、方向以及变化趋势等特征,依据模糊规则库做出模糊推理,能自动调整PID参数,可达到更加满意的控制效果.利用设计的模糊自适应PID控制器,对磁悬浮控制系统中钢球的悬浮位置实现了精确的控制.实验结果表明,模糊自适应PID控制器可以使磁悬浮控制系统拥有较好的稳态和动态性能.     

模糊免疫参数自整定PID控制系统设计及仿真

为了提高模糊PID控制器的控制性能,将模糊参数自整定与免疫进化算法相结合,设计了一种模糊免疫参数自整定PID控制系统。该控制系统首先利用模糊规则,在线调整控制系统的kp,ki,kd,利用免疫机理修正非线性函数f,然后利用免疫修正环节进一步调整PID控制系统的参数。数字仿真结果表明,新的模糊免疫参数自整定PID控制系统具有稳定性好、响应速度快等特点,具有很高的应用价值。     

基于自适应Fuzzy-PID控制的变截面板簧AGC控制系统

以PID控制作为调节系统的主要手段,提出了将模糊控制和PID控制结合起来应用于变截面板簧轧制控制系统的方法,构成了一个参数自整定的模糊PID控制器.通过模糊规则在线调解PID的各项参数,达到了改善系统性能的目的.Matlab仿真实验结果表明:控制系统的响应曲线性能较好,响应速度较快,超调量小,稳态精度高.     

模糊PID控制在水位控制中的应用与仿真

水位控制系统具有非线性、非最小相位、时滞和强耦合,难以建立精确的数学模型。本文在分析常规PID控制器局限性的基础上,运用模糊逻辑,借鉴三冲量控制方法,将模糊规则整定PID参数的控制方法引入锅炉水位控制中,设计出一种模糊PID控制器,对PID三个参数在线整定。仿真研究和在实验室的实际应用表明,模糊PID控制器特性比常规PID控制器更优良,能有效地改善控制效果。     

模糊PID控制在汽车ABS中的应用与仿真研究

ABS是一种变工况、非线性的系统，参数自整定模糊PID控制可以利用模糊控制规则对PID参数进行在线修改，因而具有较好的自适应能力．设计了一种参数自整定模糊PID控制器，在分析单轮汽车模型的基础上，探讨了其在汽车ABS上的应用．采用模糊控制、PID控制、模糊PID控制三种方法分别对汽车ABS进行仿真研究，结果表明：模糊PID控制方法兼备了前面两种方法的优点，可以达到更好的控制效果．     

基于模糊PID的变频水泵恒压供水系统仿真

针对中央空调机组的恒压供水问题提出了一种基于模糊PID控制器在线调整PID参数的变频水泵恒压供水系统.讨论了如何确定模糊PID控制器的隶属函数和模糊规则的问题,利用MATLAB软件中的模糊控制工具箱和Simulink对系统进行了仿真实验,并对常规PID控制器和模糊PID控制器分别选取了两组不同的系统传递函数,模糊PID控制器通过输出调整量ΔKp、ΔKi、ΔKd,对PID的参数Kp、Ki、Kd进行了在线调整.仿真实验结果表明模糊PID控制器不仅能有效抑制超调现象,提高系统的响应速度和稳态性能,而且对系统结构参数变化的适应能力也更强.     

模糊控制器在高阶水位控制中的设计及应用

在高阶大惯性环节对象的控制问题中 ,采用普通PID难以实现其良好的控制作用 .设计了一种基于模糊控制原理的模糊PID参数自适应控制器和模糊控制器 ,根据偏差和偏差变化率来实时调整参数 ,水位控制实验结果表明 ,这种模糊控制器比常规PID控制器有更好的控制效果 ,明显改善了系统的动态性能和稳态性能 .     

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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