机动天基平台惯性/天文组合导航的研究

为了实现机动天基平台的长时间、高精度和低成本自主导航,采用了低精度惯性导航系统和天文导航系统进行组合。以扩展卡尔曼滤波算法为基础,通过建立系统状态方程和量测方程,并进行量测方程的线性化,将捷联惯导和星敏感器分别测得的姿态信息进行数据融合,估计出组合导航系统的误差状态量,从而修正捷联惯导系统的导航参数。仿真结果表明,在1000s内,平台姿态角误差稳定收敛在20?,定位误差优于纯惯导解算,证实了该方案的实用性。     

Fuzzy Filter Design for Affine Systems with Sensor Faults: A Dynamic Event-Triggered Approach

This study addresses the issue of dynamic event-triggered-based filtering for fuzzy affine systems. To alleviate the utilization of constraint bandwidth resources and improve the efficiency of the signals exchange, a dynamic event-triggered protocol is forwarded to regulate the trigger instants with objective system states. Meanwhile, the nonhomogeneous Markov process is proposed to characterize the dynamic behaviors of sensor faults, where the time-varying transition probabilities belong to a c...     

挠性航天器大角度机动的振动抑制控制

建立了带变速控制力矩陀螺群的挠性航天器的动力学模型,应用误差四元数来描述姿态运动,将星体大角度姿态机动问题转化为误差四元数的调节问题.针对挠性航天器三轴同时姿态机动时挠性附件的振动抑制问题,提出了基于动态输出反馈控制的振动抑制方法,设计了仅利用姿态四元数而无需以角速度测量、挠性变形位移及速率测量作为反馈的动态控制规律.基于Lyapunov方法证明了所设计的动态控制器保证了姿态的渐近稳定和模态振动的衰减.基于Matlab/Simulink进行了仿真验证,结果表明了所提出的控制方法的可行性和有效性.     

网络教学平台服务质量评价体系构建

为了客观合理地评价网络教学的服务质量,在剖析网络教学特点的基础上,分析了网络教学质量控制要点,最后系统地从学生、教师、网络资源和网络平台四个维度提出了网络教学平台服务质量评价体系,以促进网络教学可持续发展.     

CORRECTION FOR COLLOCATION SOLUTIONS OF WIENER－HOPF EQUATIONS

ＣＯＲＲＥＣＴＩＯＮＦＯＲＣＯＬＬＯＣＡＴＩＯＮＳＯＬＵＴＩＯＮＳＯＦＷＩＥＮＥＲ－ＨＯＰＦＥＱＵＡＴＩＯＮＳ￥ＳＨＩＪｕｎ；ＬＩＮＱｕｎ（ＩｎｓｔｉｔｕｔｅｏｆＳｙｓｔｅｍｓＳｃｉｅｎｃｅ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，Ｂｅｉｊｉｎｇ１０００８０，...     

Characteristics of dry friction backward whirl-A self-excited oscillation in rotor-to-stator contact systems

In this paper, the response characteristics of dry friction backward whirl of a general rotor/stator model, which accounts for both the dynamics of the rotor and the stator as well as the friction and the deformation at the contact surfaces, are investigated. The existence boundaries and the whirl frequencies of the dry friction backward whirl are determined analytically. It is found that there are two or three existence boundaries of the dry friction backward whirl that usually form two existence regions, ...     

A novel water-soluble anionic conjugated copolymer containing poly（p-phenylene vinylene） segments： Copolymer synthesis and multilayer construction by assembling poly（diallyl dimethyl ammonium chloride）

This paper reports the synthesis of a water soluble conjugated polymer poly（p-phenylene vinyleneco-sodium methacrylate） （ws-P（PV-co-SMA）） and the multilayer of the derived copolymer assembling poly（diallyl dimethyl ammanium chloride） （PDDA）. The self-assembling process of the multilayer was monitored by UV-vis absorption spectroscopy, and the data indicated a linear increase in film thickness with a number of ws-P（PV-co-SMA）/PDDA bilayers. The alternative deposition of ws-P （PV-co-SMA） and PDDA allowed the insertion of a non-conjugated layer between the conjugated layers, thus the migration of the photogenerated polarons was effectively confined in the isolated ws-P （PV-co-SMA） chains. Consequently, the photoluminescence quantum yield reached 0.68, 30 times higher than that of pure poly（p-phenylen vinylene）. The distinct electronic interactions between conjugated segments were confirmed by comparative analyses of the excitation spectra and time-resolved photoluminescence spectra of ws-P（PV-co-SMA） solid film and the assembled multilayers. The confinement effect of the PDDA layer on the photogenerated carriers was verified by the surface photovoltage spectroscopic measurement on both ws-P（PV-co-SMA） solid film and self-assembled multilayers.     

Ferroelectric polarization,domains structures and magnetic property of Y1-xInxMnO3

The vortex domains, structural properties and ferroelectric polarization in Y1-xInxMn O3 with 0 B x B 0.6have been extensively investigated in well-characterized samples. X-ray diffraction measurements demonstrated that the lattice parameters change continuously following the substitution of In for Y. Measurements of magnetic susceptibilities revealed that In substitution could visibly affect the magnetic transition and low-temperature magnetic properties. Transmission electron microscopy study showed that In substitution could result in notable decrease of the size of ferroelectric vortex domains. Cs-corrected scanning transmission electron microscopy observations and our careful analysis on atomic-poling configurations demonstrate that the ferroelectric polarizations of Y1-xInxMn O3 are suppressed with the increase of In content.     

Coherent change detection of fine traces based on multi-angle SAR observations

Coherent change detection(CCD) is an effective method to detect subtle scene changes that occur between temporal synthetic aperture radar(SAR) observations. Most coherence estimators are obtained from a Hermitian product based on local statistics. Increasing the number of samples in the local window can improve the estimation bias, but cause the loss of the estimated images spatial resolution. The limitations of these estimators lead to unclear contour of the disturbed region, and even the omiss...