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In this paper, a multivariable direct adaptive controller using multiple models without minimum phase assumption is presented
to improve the transient response when the parameters of the system jump abruptly. The controller is composed of multiple
fixed controller models, a free-running adaptive controller model and a re-initialized adaptive controller model. The fixed
controller models are derived from the corresponding fixed system models directly. The adaptive controller models adopt the
direct adaptive algorithm to reduce the design calculation. At every instant, the optimal controller is chosen out according
to the switching index. The interaction of the system is viewed as the measured disturbance which is eliminated by the choice
of the weighing polynomial matrix. The global convergence is obtained. Finally, several simulation examples in a wind tunnel
experiment are given to show both effectiveness and practicality of the proposed method. The significance of the proposed
method is that it is applicable to a non-minimum phase system, adopting direct adaptive algorithm to overcome the singularity
problem during the matrix calculation and realizing decoupling control for a multivariable system.
Supported by the National Natural Science Foundation of China (Grant Nos. 60504010, 60864004), the National High-Tech Research
and Development Program of China (Grant No. 2008AA04Z129), the Key Project of Chinese Ministry of Education (Grant No. 208071),
and the Natural Science Foundation of Jiangxi Province (Grant No. 0611006) 相似文献
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目前各种国产机动平地机,与国外先进平地机相比,不仅平地效率低,在行驶与制动方面还存在操作困难、易打滑、难制动、噪音大等方面的缺陷,文中提出了一种新型机动平地机行驶系统和停车制动系统的设计方案,解决了原国产机存在的许多缺陷,对于提高我国平地机设计水平有重要意义. 相似文献
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Yang ShuiYuan Hong Shen Li MingPei Qing XinYu Guo LiPeng Guo YiHui Wang CuiPing Liu XingJun 《中国科学:技术科学(英文版)》2021,64(2):400-406
In this study, two Cu-Al-Mn-Fe polycrystalline alloys were prepared, and their microstructure, reversible martensitic transformation, mechanical properties and shape memory effects were investigated. The results show that the reversible martensitic transformation temperatures of the studied alloys are between room temperature and 373 K, which are suitable for practical applications. Two typed martensites of 18R and 2H coexist both in two alloys. The bcc β(FeAl) nanoparticles are Fe-rich, Mnrich and Cu-poor, whereas the martensite is Cu-rich, Fe-poor and Mn-poor. The size of nanoparticles ranges from tens to hundreds of nanometers. Full shape recovery property is displayed in Cu-12.9Al-4.5Mn-2.6Fe alloy all the time while applying different deformation from 5% to 8%. The maximum recoverable strain is up to 4.4% with a recovery rate of 100%. 相似文献
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螺栓啮合螺纹段的轴力、等效应力分布及摩擦的影响分析 总被引:5,自引:0,他引:5
采用有限元数值模拟方法,考虑螺栓材料的弹塑性性质,计算分析普通三角形螺纹螺栓-螺母副在轴向力作用下的内力、应力和变形规律。给出不同总轴力下螺栓螺纹段中轴向力和螺牙根部最大等效应力沿轴向的非线性分布规律和总轴力在各圈螺纹上的分配关系;对由轴对称二维螺牙模型、三维回转螺牙模型和三维螺旋线型螺牙模型计算得到的对应各圈螺纹上的轴向力和螺牙根部最大等效应力进行比较,指出在工程分析中,对于轴向载荷作用情况,可近似将螺旋线型螺牙简化为三维回转螺牙;给出螺栓绕轴线的转角和各圈螺纹上传递的轴向力随螺牙界面摩擦因数的非线性变化规律,得出轴向外力下螺纹段最大等效应力随摩擦因数增大而减小的规律。 相似文献
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杨毅慧 《中国服装(北京)》2006,(16):15-15
十多年前,在民间考古活动的影响下,瑞典人掀起了对沉船“哥德堡号”的热情。2006年7月18日,历经10年,耗资3000万美元重建的“哥德堡Ⅲ号”载着瑞典国王,王后等王室成员,重返广州,开始了中瑞两国人民一段新的梦想之旅。瑞典国王,王后兴致勃勃地参观了古港特设的仿古布店“天意莨绸坊”,深圳市梁子时装实业有限公司将两套天意莨绸时装,作为礼物赠送给了国王夫妇。瑞典王后对这种独具岭南特色的丝绸时装备感兴趣,向天意首席设计师梁子仔细询问了这种面料的各种情况。 相似文献
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增压是提高柴油机功率的最主要。最有效的途径。随着增压压力的提高。柴油机的功率成比例的提高。因此增压器一旦工作异常或发生故障对柴油机的工作性能影响很大。根据调查发现。增压器故障在柴油机故障中所占的比例正在逐年增大。而其中又以增压器的喘振最为常见。且危害也很大。本文即针对柴油机涡轮增压器的喘振故障。压气机特性的探讨。以及压气机与柴油机的配合的讨论。进而深入分析增压器喘振故障的理论原因。并给出一些实际情况中引起喘振的具体因素和相应的预防、排除方法。 相似文献