共查询到20条相似文献，搜索用时 92 毫秒
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依据柔性机械臂动力学模型建立了控制模型及状态空间方程的一般形式,并将线性二次型最优理论应用于柔性机械臂的振动控制.介绍了线性二次最优控制中加权矩阵的作用,讨论了加权矩阵对控制系统的影响,依线性二次型最优控制理论,用Matlab数值仿真比较了柔性机械臂的振动控制效果,仿真结果表明,柔性机械臂的弹性振动得到有效抑制. 相似文献
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柔性机械臂的振动严重影响其应用效果。因此,要以单关节柔性机械臂为研究对象,使用LabVIEW软件运用PPF的算法进行柔性机械臂的振动控制。文章首先介绍了PPF算法原理,然后详细论述了仿真过程。仿真结果表明,PPF算法能有效控制柔性机械臂的前两阶模态振动。 相似文献
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本文根据刚柔分解控制策略了加速传感器的在柔性机械手振动控制中的应用。通过硬件电件电路分 加速度传感器输出信号中的不同分量，再分别采用直接加速度反馈法和模糊控制法实现对单链杆柔性机械手的振动控制，并给出了实验结果。 相似文献
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针对柔性悬臂梁的振动问题,开展了PPF振动控制实验研究．首先研究了单模态PPF控制器和多模态PPF控制的主动控制技术,介绍了各控制参数的调整方法,然后建立柔性悬臂梁的实验装置,对系统进行了参数辨识,并进行了PPF控制实验．实验结果表明,压电陶瓷驱动的PPF振动控制对柔性悬臂梁振动抑制具有良好的效果,而且设计方法简单,易于工程实现． 相似文献
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机械臂的关节柔性是影响机械臂动态精确度和稳定性的重要因素,必须考虑机械臂关节柔性对精度的影响,精确的关节动力学模型是机械臂系统设计、分析和控制的基础。本文以二自由度机械臂为研究对象,运用Lagrange方法建立了考虑关节柔性的动力学方程,并针对单连杆设计Backstepping控制律,同时给出了李雅普洛夫稳定性证明,最后基于simulink进行了仿真,验证了控制器设计的合理性。 相似文献
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在进行噪声和振动的主动控制中,压电作动片因其具有重量轻、安装布置容易等优点,越来越受到重视.本文研究了压电复合纤维板的弯曲特性,对不同的边界条件、复合纤维板的不同纤维角度、不同的电压、压电作动片的不同厚度,具体分析了复合板的纵向位移.仿真结果显示了不同的边界条件对智能结构静态形状控制的影响. 相似文献
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随着建筑形式的多样化以及结构高度、跨度的增大,结构在地震和风等动力荷载作用下的振动问题也日益突出,单纯通过结构设计中增大构件截面或者增强刚度的方法越来越显示出其不合理性,与此同时,智能材料的研究与应用给结构振动控制技术开辟了新的天地,已成为结构工程领域最具有前沿性的发展方向之一。本文根据主动控制力学模型,进行了压电主动杆件位置优化的推导分析,并介绍了优化布置的实现方法,结合一个七层框架结构进行了仿真模拟,可以看到,对结构进行智能控制之后效果显著,并且压电主动杆的控制效果不因输入地震波的不同而不同,同时与结构自身参数有很大关系,通过布置位置的优化,可以实现在布置较少主动杆的同时达到良好控制效果的目标。最后通过一个三层框架结构试验验证了优化方法,较好的实现了主动控制。 相似文献
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为了快速实现柔性机械臂的精确定位,减小机械臂移动过程中的抖动,本文利用Lagrange方法建立了柔性机械臂的动力学模型,并在此基础上利用线性二次最优控制LQR（Linear Quadratic Regula-tor）方法设计了机械臂快速定位控制器.在LabVIEW虚拟仪器软件中进行了仿真实验验证,结果表明：利用 LQR方法控制的机械臂系统响应更快,能更快地到达目标位置,速度提高约2.8倍,大幅减小了达到稳态的时间,同时削弱了运动过程中产生的抖动,机械臂的整体性能得到提高. 相似文献
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基于滑模控制的悬臂梁振动控制实验研究 总被引：1，自引：0，他引：1
文章首先介绍了滑模面和控制函数的选取,然后用Matlab／Simulink建立基于滑模控制的仿真模型,通过实时仿真系统dSPACE实现仿真模型与实验硬件装置的连接。采用压电陶瓷传感器采集悬臂梁振动位移,控制器输出经压电陶瓷驱动器对悬臂梁进行振动控制,控制目标是获得短的调节时间,并减小滑模控制常有的抖振．实验结果表明,设计的滑模控制器对悬臂梁的振动具有很好的抑制作用． 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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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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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 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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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献