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211.
A new active fault tolerant control scheme based on active fault diagnosis is proposed to address the component/actuator faults for systems with state and input constraints. Firstly, the active fault diagnosis is composed of diagnostic observers, constant auxiliary signals, and separation hyperplanes, all of which are designed offline. In online applications, only a single diagnostic observer is activated to achieve fault detection and isolation. Compared with the traditional multi-observer parallel diagnosis methods, such a design is beneficial to improve the diagnostic efficiency. Secondly, the active fault tolerant control is composed of outer fault tolerant control, inner fault tolerant control and a linear-programming-based interpolation control algorithm. The inner fault tolerant control is determined offline and satisfies the prescribed optimal control performance requirement. The outer fault tolerant control is used to enlarge the feasible region, and it needs to be determined online together with the interpolation optimization. In online applications, the updated state estimates trigger the adjustment of the interpolation algorithm, which in turn enables control reconfiguration by implicitly optimizing the dynamic convex combination of outer fault tolerant control and inner fault tolerant control. This control scheme contributes to further reducing the computational effort of traditional constrained predictive fault tolerant control methods. In addition, each pair of inner fault tolerant control and diagnostic observer is designed integratedly to suppress the robust interaction influences between estimation error and control error. The soft constraint method is further integrated to handle some cases that lead to constraint violations. The effectiveness of these designs is finally validated by a case study of a wastewater treatment plant model. 相似文献
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213.
孟李林 《微电子学与计算机》2008,25(3):32-34
提出了一种存储器设计重构的新思想,给出了两种不同的异步时分交换电路的设计方案.试验结果表明,采用设计重构实现FIFO和DM两块存储器合并的设计方案能够减少存储器的使用数目,缩小芯片的面积,从而简化电路设计复杂度,降低芯片的功耗,提高芯片的可靠性和整体性能. 相似文献
214.
鹅掌楸树叶在风中的变形与振动 总被引:2,自引:0,他引:2
树叶的空气动力与流固耦合特性研究在树木保护、新发电技术开发、太阳能帆板设计等方面具有重要意义.Vogel首次发现树叶在较高风速下具有形状重构以避免受损害的能力.Vogel实验时叶柄端部是简支的,与叶柄与树枝的自然连接方式不同.在本文的研究中,叶柄端部是固支的,叶片垂直悬挂,正面或反面迎风.在风速0~27 m/s范围内,存在两种叶片静止状态,即飞翼形稳定和锥形稳定;还有3种叶片振动状态,即低频摆动、第1和第2高频振动.这5种状态由5个临界风速决定.通过70余片树叶测试结果的统计,得到了树叶每个状态存在的概率,及每个临界风速的期望值.流动显示发现树叶变形后其尾流中存在旋涡脱落现象.天平测量发现叶片阻力系数随叶片雷诺数的增大而减小并逐渐接近于0.1.引入悬臂梁模型,采用测量的叶片气动力,对叶柄静态弯曲形状进行计算,结果表明当风速由0逐渐增至5 m/s时,叶柄向下游弯曲迅速;但风速由5 m/s进一步增大时,向下游的弯曲则变慢. 相似文献
215.
This paper aims to introduce a time partitioning algorithm which is an important step during the design process for fully reconfigurable systems. This algorithm is used to solve the time partitioning problem. It divides the input task graph model to an optimal number of partitions and puts each task in the appropriate partition so that the latency of the input task graph is optimal. Also a part of this paper is consecrated for implementation of some examples on a fully reconfigurable architecture following our approach. 相似文献
216.
人工生命科学就是研究生物机体的特征,胚胎电子学介绍了新一代生物灵感容错FPGA系列,适合于人工生命的研究,胚胎电子阵列通过硬件冗余和阵列重构机构获得容错功能,本文论述和分析了根据κ-out-of-m可靠性模型的胚胎电子阵列的重构策略。讨论了行取消和细胞取消两种方案。 相似文献
217.
Green optical backbone networks: virtual topology adaptation using a page rank‐based rating system 下载免费PDF全文
Panagiotis Melidis Petros Nicopolitidis Georgios Papadimitriou Emmanouel Varvarigos 《International Journal of Communication Systems》2015,28(16):2112-2121
An energy‐aware virtual topology rating system is proposed in this work, which can be utilized as a tool during the virtual topology reconfiguration procedure in an optical backbone network in order to reduce its energy consumption. It is well known that maintaining a static virtual topology in Internet Protocol (IP)‐over‐Wavelength Division Multiplexing (WDM) networks is not energy‐efficient. To that end, virtual topology adaptation algorithms have been developed to adjust the virtual topology to the constantly fluctuating traffic load. While these algorithms achieve significant energy savings, further reduction on the total network energy consumption can be achieved through the proposed rating system. The proposed rating system is a modified version of the page rank algorithm, which ranks websites in the Internet based on their importance. The proposed rating system attributes ratings to lightpaths, which indicate the relative significance of a lightpath in the virtual topology in terms of energy consumption. The rating can be used during the routing procedure as an energy efficiency indicator, in order to increase the number of lightpaths that are deactivated from the reconfiguration mechanism and increase the utilization per lightpath. The proposed reconfiguration scheme (page rank‐based virtual topology reconfiguration) achieves up to 12% additional energy savings in comparison to an existing virtual topology reconfiguration algorithm at the cost of slightly increased average hop distance. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
218.
Liuqing He Wenbiao Zhang Qijie Mo Wenjie Huang Lichun Yang Qingsheng Gao 《Angewandte Chemie (International ed. in English)》2020,59(9):3544-3548
Heterostructured Mo2C‐MoOx on carbon cloth (Mo2C‐MoOx/CC), as a model of easily oxidized electrocatalysts under ambient conditions, is investigated to uncover surface reconfiguration during the hydrogen evolution reaction (HER). Raman spectroscopy combined with electrochemical tests demonstrates that the MoVI oxides on the surface are in situ reduced to MoIV, accomplishing promoted HER in acidic condition. As indicated by density functional theoretical calculations, the in situ reduced surface with terminal Mo=O moieties can effectively bring the negative ΔGH* on bare Mo2C close to a thermodynamic neutral value, addressing difficult H* desorption toward fast HER kinetics. The optimized Mo2C‐MoOx/CC only requires a low overpotential (η10) of 60 mV at ?10 mA cm?2 in 1.0 m HClO4, outperforming Mo2C/CC and most non‐precious electrocatalysts. In situ surface reconfiguration are shown on W2C‐WOx, highlighting the significance to boost various metal‐carbides and to identify active sites. 相似文献
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220.
提出了参数化系统级模型.该模型不依赖于具体结构,以任务布局与重构处理分离的两级结构处理任务调用,通过参数方式实现不同设计方案的硬件结构和布局算法的配置.采用SystemC语言对模型进行了建模验证,仿真结果表明,通过指定上下文的下载、配置和执行等时间开销参数,在系统级设计空间探索中,能很好地模拟动态重构协处理器. 相似文献