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为了维持锅炉恒温水箱的温度,采用改进PID控制方法,并对控制方法进行仿真。给出锅炉恒温水箱的工作原理,建立锅炉温度传递函数。引用PID控制方程式,采用免疫遗传算法优化PID控制参数,实现PID控制器参数实时优化,通过仿真验证优化后锅炉恒温水箱温度输出误差。结果表明:采用传统PID控制方法,恒温水箱温度输出误差最大值为5℃,误差波动幅度较大;采用神经网络PID控制方法,恒温水箱温度输出误差最大值为3℃,误差波动幅度幅度较小;而采用改进PID控制方法,恒温水箱温度输出误差最大值为1℃,误差波动幅度最小。采用免疫遗传算法优化PID控制参数,能够提高锅炉恒温水箱温度控制精度。 相似文献
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针对智能热泵精度高、稳定性强的恒温环境要求,提出了一种以DSP2812和STM32为硬件平台的温度调节控制系统.该恒温控制系统是以优化的数字PID控制算法为基础,辅以首次阀门开度技术、温度斜率技术和阀门跟踪技术.同时还有人机互动界面,可以在线设置PID参数和出水温度.该系统可以在5min之内达到60℃的设定温度,并且能够有效地抑制温度超调,最终实现恒温出水. 相似文献
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针对目前小家庭夏天不能酿米酒,冬天要用稻草或棉被包着酿米酒的问题,设计并制作了一个以STM32F103C8T6作为主控芯片的酿酒恒温箱系统。通过DS18B20温度传感器采集恒温箱内的温度,用PID算法精确控制温度,采用OLED进行数据显示,利用按键设定目标温度和PID参数,接着用C#语言编写了上位机软件,最后用SolidWorks软件设计控制器外壳并用3D打印。本系统可以恒温在19~40℃之间的任意一个温度上,精度达到0.1℃,超调2%,箱体体积可变换,运行0.5 h后系统趋于稳定,利用本系统人们可以随时酿米酒。 相似文献
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介绍了一种采用自校正模糊PID控制算法的PCR芯片实验室温度控制系统。该系统将模糊推理控制与PID控制相结合,利用PCR芯片上溅射的Pt电阻获取温度信号,通过PID精确输出控制在芯片背面直接制备的微加热器和外加的半导体致冷器件,实现了PCR芯片的高精度快速变温控制,可用于近场光学显微镜实时探测PCR扩增反应过程中荧光信号的近场分布,为实现高灵敏度DNA定量检测提供了必要条件。 相似文献
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基于DSP的微机励磁调节器的设计与实现 总被引:12,自引:0,他引:12
论述了基于DSP(Digital Signal Processubg)芯片TMS320LF2407A的微机励磁调节器的设计原理及实现过程.利用DSP芯片可快速执行傅氏算法的优点,通过采用同步采样ADC芯片ADS8364实行交流同步采样的方法,对同步发电机出口端的定子电压、电流进行准确测量.通过PID和最优控制的方法,得到精确的PWM控制信号输出,并且利用DSP芯片上的串行通信接口SCI和CAN控制器接口,实现多机之间和与上位机之间的调试和监控通信。 相似文献
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为解决传统恒温控制在工农业应用中自动化程度低、精准度不高以及稳定性差等问题,设计了一种基于新型模糊 PID( Proportion Integration Differentiation) 控制理论的自动控制系统。该系统应用 STM32 芯片对温度量进行采集和实时控制,使用矩阵键盘和液晶屏作为人机交互设备,引入新型模糊 PID 控制算法,构建新型模糊PID 控制器,通过迭代算法整定比例、积分和微分参数值,得到加热控制量,控制器根据该控制量按对应的PWM( Pulse Width Modulation) 高电平占空比输出电流量对半导体制冷片进行加热。实验表明,该系统能快速采集系统温度并进行实时控制,将系统温度稳定在预期温度,系统理论绝对误差为 0. 1 ℃ ,实际测量误差为0. 5 ℃ 。系统较好地实现了温度自动检测与控制,解决了自动化程度低、精准度不高以及稳定性差的问题。 相似文献
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喷绘机是采用数字压电技术在特制的基材上打印大幅面彩色广告画面的大型设备。控制系统是喷绘机的核心,承担数据传输、运动控制、喷头驱动控制等功能。设计的喷绘机控制系统采用32位嵌入式Jupiter芯片作为主控制器,利用ISP1581芯片实现USB2.0高速数据传输,并采用318SLX高精度喷头实现高精度打印,从而使喷绘设备具有喷绘速度快、分辨率高、成本低、系统运行可靠等优点。 相似文献
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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. 相似文献
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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. 相似文献
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Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
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The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
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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。 相似文献
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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. 相似文献
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Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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 相似文献