共查询到20条相似文献，搜索用时 62 毫秒
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《邢台职业技术学院学报》2019,(5):67-70
加气站的工业气体输送给用户时,为了便于气体的输送,尤其在气温较低时通常需要对高压气体预加热,在预加热过程中,温度的精确控制非常重要。在温度控制系统中,采用温度传感器采集气箱内温度与用户设定值的比较,通过分析历史偏差、当前偏差和近期偏差,调整合适的采样周期与参数,利用PID算法实现温度的控制,效果良好。 相似文献
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在工业应用中液位控制系统非常重要,传统的三容水箱液位控制模型．是利用传统的PID实现液位控制的,但是参数太小,无法进行有效控制。采用PID控制器的自整定技术进行控制更加可靠,精度更高,但也包含不确定的因素在内。本文对比分析了传统PID和自整定技术两种控制方法。 相似文献
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针对工业现场复杂的时变系统存在的经典PID控制调节复杂、效应滞后、超调量大、稳定性差等问题,将模糊控制与内模PID控制相结合,并对滤波参数进行优化调整以适应复杂工业系统。首先,在完成模型辨识后,将内模控制等效为PID反馈控制,采用麦克劳林展开,并加入一阶时滞模型,形成等效反馈控制器的传递函数;其次,利用模糊控制策略,设计模糊内模PID控制器,利用偏差和偏差变化率实时调整内模PID的滤波参数λ;最后,分别利用MATLAB软件和功率控制装置进行仿真和测试。实验结果表明,模糊内模PID控制具有更快的响应速度和更小的超调。 相似文献
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《佳木斯教育学院学报》2016,(3)
传统的电气控制方法主要采用人工控制,该方法已经无法适应现阶段日益发展的工业要求,因此,提出一种基于改进PID节能控制的电气控制方法,将现代的电气控制的模糊理论与PID方法结合,实现PID参数在线模糊自整定的控制方法。仿真实验表明,改进的方法在电气控制过程中不仅降低了控制经费,而且控制准确程度更高,速度更快。 相似文献
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本文主要介绍了基于西门子公司s7—200系列的可编程控制器和亚控公司的组态软件组态王的温度控制系统的设计方案．编程时调用了编程软件STEP7-MicroWIN中自带的PID控制模块。使得程序更为简洁,运行速度更为理想．利用组态软件组态王设计实现GPKS无线远程监控系统的实时监控、数据的实时采样与处理．实验证明,此系统具有快、准、稳等优点,在工业温度控制领域可以进行广泛应用． 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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基于内模控制的工业控制系统仿真器鲁棒PID控制器设计 总被引：1，自引：0，他引：1
《实验技术与管理》2015,(1)
内模控制是一种基于被控对象数学模型的新型控制器设计方法,所设计的控制器具有鲁棒性强、参数整定方便等优点,已经在一些工业场合中得到了应用。为了提高学生对于内模控制方法的理解水平,该文首先简要介绍了内模控制的基本原理和内模PID控制器设计方法,介绍了工业系统仿真器实验平台的构成,并推导了其数学模型的表达式,然后利用内模控制原理为其设计了鲁棒PID控制器,通过仿真软件进行了实验验证,结果证明了内模控制方法的有效性。 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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《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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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 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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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 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