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Robust and precision motion control system of linear-motor direct drive for high-speed X-Y table positioning mechanism 总被引:1,自引:0,他引:1
Zuo Zong Liu Fang Lin Luo Rahman M.A. 《Industrial Electronics, IEEE Transactions on》2005,52(5):1357-1363
In this paper, design and implementation of an H/sub /spl infin//-based precision motion control system is presented for a high-speed linear-motor direct-drive X-Y table positioning mechanism in semiconductor wire-bonding applications. The system works with a cascaded robust feedback control, which has an inner loop velocity controller and an outer loop position controller, and an autotuning feedforward compensator. The design aim is to achieve high and consistent tracking performance even in the presence of considerable resonance uncertainties and external disturbances. Toward this aim the velocity controller is designed using H/sub /spl infin// optimization technique, based on reduced-order modeling that considers three significant resonance modes and neglects all other resonance modes having an insignificant amplitude and/or too high frequency. These neglected modes and variations of the three resonance modes from machine to machine (due to manufacturing tolerance) and/or with different operating conditions are taken care of by appropriate additive uncertainty representation in the design phase. The resulting system is validated and implemented with a profile motion of a maximum acceleration of 5.2 g (1g=9.81 m/s/sup 2/) on mass-produced wire bonding machines. 相似文献
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僵尸网络作为近年来危害互联网的重大安全威胁之一,引起了研究者的广泛关注。论文通过分析僵尸网络工作过程中各阶段表现出的异常行为特征,提出了基于异常行为监控的僵尸网络发现技术,详细阐述了僵尸网络发现系统的原理及系统框架结构,并对其关键技术进行了设计实现。 相似文献
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Chunyu Xu Ke Jin Zuo Xiao Zijin Zhao Xiaoling Ma Xuelin Wang Junming Li Wenjing Xu Shuping Zhang Liming Ding Fujun Zhang 《Advanced functional materials》2021,31(52):2107934
Wide bandgap polymer D18 with narrow photon harvesting in visible light range and small molecule N3 with near-infrared photon harvesting are adopted for building semitransparent organic photovoltaics (OPVs). To find out the optimal D18:N3 weight ratio for semitransparent OPVs, series of opaque OPVs are built with a varied D18:N3 weight ratio. The power conversion efficiency (PCE) and fill factor can be maintained over 16% and 77% in the D18:N3 (0.7:1.6, wt/wt) based opaque OPVs, respectively. The average visible transmittance (AVT) of the corresponding blend films can be achieved over 50%, demonstrating the great potential in fabricating efficient semitransparent OPVs. The semitransparent OPVs based on D18:N3 (0.7:1.6, wt/wt) are fabricated by using 1 nm Au/(10, 15, 20 nm) Ag as cathode. The thickness of Ag layers is varied to balance the optical properties and electrical properties of semitransparent top electrode. The semitransparent OPVs with 10 nm Ag achieve the highest light utilization efficiency of 2.90% with a PCE of 12.91% and an AVT of 22.49%, which should be among the best performance of reported semitransparent OPVs. This work demonstrates that the wide bandgap polymer donor with narrow photon harvesting in visible light range has great potential in preparing efficient semitransparent OPVs. 相似文献
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Organic solar cells (OSCs) have achieved rapid advance due to the continuous development of high-performance key materials.Recently,the power conversion efficiencies (PCEs)of OSCs under 1 Sun condition (AM 1.5 G,100 mW/cm2) are striving toward 19%[1-5].The PCE improvement benefits from the largely enhanced short-circuit current density (Jsc) and fill factor (FF).However,these cells show relatively low open-circuit voltage (Voc) around 0.8-0.9 V.The rise of Internet of Things (loT) industry has promoted the indoor application of solar cells.OSCs can afford higher PCEs under various indoor light as compared to 1 Sun condition[6,7],but they present lower Voc[8].Fabricating tandem devices is an effective strategy to boost the performance of OSCs.Sub-cells with syn-chronously high Voc,Jsc and FF are highly desired in tandem cells,while these sub-cells are still limited[9].Thus,improving Voc without sacrificing Jsc and FF is an urgent mission in OSCs. 相似文献
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