共查询到20条相似文献，搜索用时 62 毫秒
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介绍了以FX2N-48MT可编程序控制器为核心构成的小型温控示教系统,利用模拟功能模块和PLC的功能指令,在外围电路的配合下实现信号采集、A/D转换与处理及PID运算控制。 相似文献
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朱卓城 《实验室研究与探索》2010,29(11)
通过看具体操作及供水系统运行的演示实验投影,使学生了解恒压供水系统的组成和基本原理,从实际调试中看清外围输入输出连接方法、运行程序的设计、PLC在恒压供水系统中对模拟量的处理和PID控制的基本过程。认识本恒压供水系统借助变频器无级调速特点,通过闭环控制实现了节能、可靠、自动化程度高等优点的供水目的。 相似文献
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《实验室研究与探索》2016,(8):61-63
结合机械电子专业的学科特点,基于多课程交叉融合的培养需求,设计了PLC的温度控制实验系统,系统具备温度的实时监控、温控曲线的准确跟踪等功能。以PLC为控制核心,采用V/F转换器和PLC的高速计数功能实现了串行A/D转换,并利用PLC的定时器产生脉宽调制(即PWM)波形替代了D/A模块;软件上设计了温度控制曲线,并采用分段拟合的方法修正频率-温度曲线,弥补了常规PID算法的缺陷,实现了温度的闭环控制。该实验系统利用实验室现有的实验资源进行搭建,降低了实验成本,提高了实验设备的利用率。 相似文献
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在卷烟梗丝 BD 干燥工艺中,对梗丝温度和含水率的精确控制是关键环节。根据烟厂客户需求和梗丝BD 干燥工艺规范,分析 PID 控制算法,结合实际生产情况,设计实现满足企业现代化需求的 PID 控制程序。PLC 通过调用新型 PID 控制程序可精确控制风机风门开度和热交换器蒸汽流量,从而实现梗丝快速干燥定型,提高梗丝填充能力和质量。开车后系统运行正常,满足实际工程需求。 相似文献
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《武汉职业技术学院学报》2014,(1)
CNC软件和PLC软件是数控系统控制软件的两大部分,通过对CNC和PLC的分析研究,总结了在OKUMA OSP系统PLC程序中主轴速度修调开关状态数据的读入和处理;研究了修调数据的读入和校验、修调数据的格式转换、修调百分率译码等内容。为数控机床电气设计和维修人员提供了必备知识。 相似文献
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为了实现工业控制系统的PID控制,利用PLC与PID指令建立控制器,分析模拟量、脉冲量输入输出系统信号传递过程,设计三菱PLC程序实现变频闭环调速系统控制过程。文章通过实例论述PID控制系统构建,提出脉冲量输入输出控制方式,具备同类控制系统建设的参考价值与实际意义。 相似文献
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针对工业控制领域中的液位自动高精度的控制问题,重点研究基于PLC的液位控制技术.分析PLC控制原理和PLC控制系统的组成结构,构建了基于PLC的液位自动控制系统组成结构.针对液位控制系统中各实现模块进行分析,主要对液位控制系统中的控制模型和控制方法进行了重点研究.集中基于PID智能控制模型,分析PID控制模型的实现原理和控制机构,利用围绕如何提高控制系统的控制精度和响应速度,设计基于模糊PID的控制模型,提高了液位控制系统的控制精度及响应速度. 相似文献
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本针对如何利用可编程序控制器（PLC）改进啤酒自动生产线控制系统，详细论述了PLC控制系统的控制方案及软、硬件的设计方法，并对在实际应用中易出现的问题进行了分析和解决。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献