陀螺仪壳体翻滚系统

为提高陀螺仪的精度，采用壳体翻滚自动补偿与壳体有关的漂移误差力矩。介绍了一种无刷直流伺服电动机数字控制系统，并与俄罗斯－Ⅱ－15仪表的模拟控制系统做了比较。同时在运动件和固定件之间设计了一套特殊的导电装置。实验表明该导电装置使用寿命长、可靠性高。     

壳体旋转对由恒速磁场引起的漂移误差的调制作用

陀螺仪通过外加旋转磁场恒速时,如果磁场旋转轴与转子动量矩轴不重合,将产生干扰力矩引起自由转子陀螺仪的漂移误差。文中建立了壳体翻滚的运动坐标系,分析了静止坐标系、平台坐标系、壳体坐标系、光电传感器坐标系之间的运动关系;最后从理论上证明了壳体旋转对该项漂移误差的调制作用。分析结果对于研制静电陀螺仪壳体旋转系统具有一定的参考价值。     

空间稳定系统壳体翻滚失准角误差精确补偿

壳体翻滚是提高空间稳定系统长时间工作精度的技术手段之一,但其失准角误差将引起速度和姿态扰动。对该误差进行建模、标定与补偿是解决此问题的有效措施。在误差补偿时,由冗余角变化导致的交叉耦合影响对长航时高精度惯导系统是不能忽视的。根据壳体翻滚失准角误差矢量的几何投影关系,建立物理平台坐标系(P系)与陀螺三面体坐标系(G系)之间的坐标转换关系,分析冗余角变化引入的交叉耦合影响,并进行计算机仿真和实际试验。结果表明:冗余角使P系相对G系沿z向的角运动附加极轴壳体翻滚周期分量,其幅值为失准角与冗余角正切函数的乘积;误差补偿考虑这一项,东速、横摇和航向精度十天可提高30%⁵0%。     

壳体翻滚失准角模型最小二乘辨识方法

为了提高空间稳定惯性导航系统的姿态角测量精度,建立了壳体翻滚失准角模型,给出了从壳体翻滚失准角幅值和初始相位到当地水平坐标系下的姿态转换矩阵的传递规律.利用静态下平台运动学方程中壳体翻滚失准角与框架角的定量关系,进行了壳体翻滚失准角模型最小二乘辨识方法仿真,结果表明模型系数估计精度是足够的.针对实验系统,经过模型补偿,姿态角计算误差峰峰值小于0.5′.     

转台控制系统的DSP实现

从软、硬件两方面介绍了一种基于TMS320F206的数据采集及控制系统在转台控制中的应用。这种以高速SP芯片为核心的控制系统,能实现更先进的控制算法。     

MEMS环形陀螺仪正交误差补偿系统设计

以一种电容式全对称S形弹性梁硅基环形波动陀螺仪为对象,对其正交误差进行了相关的研究,以提升MEMS环形陀螺仪的精度.首先,介绍了环形陀螺仪结构,同时以此结构为基础分析了正交误差产生的原因及影响;然后,对环形陀螺仪检测通道的输出信号进行量化分析,并根据正交力校正法设计了环形陀螺仪的正交误差补偿系统;最后,对加入正交误差补...     

光纤捷联航姿基准系统的设计与实现

针对光纤陀螺仪及捷联系统的特点,研究并实现了一种基于光纤陀螺仪的捷联航姿基准系统。以PC/104作为导航计算机,采用I/F转换回路及计数线路构成加速度计的数字信号采集系统,采用智能多串口线路完成各模块之间的通讯任务,构成捷联式航姿基准系统原理样机。在此基础上,设计了系统的机械编排方案、传感器的误差补偿方案和闭环卡尔曼滤波器。样机的测试结果表明:样机满足系统设计要求,在温控环境中,其精度优于基于挠性陀螺仪的捷联航姿系统。     

基于可控式被动阻尼的静电陀螺仪启动控制系统

静电陀螺仪(ESG)的启动阻尼是一个转子最大惯性主轴与转轴对准的过程。采用直流磁场的可控式被动阻尼方法有效地解决了转子极性倒置问题。中介绍了基于可控式被动阻尼ESG启动控制系统的设计和研制，该系统以浮点DSP芯片TMS320C32为核心电路，具有转子阻尼、极性识别与控制、故障检测、转速测定、恒速控制和RS232通讯等功能。在气浮装置上证实了所研制的系统能有效实现上述功能。     

寻北系统陀螺仪与g有关项漂移的场地标定

根据寻北系统的工作原理，提出了一种与g有关的陀螺仪漂移误差的场地快速标定方法。通过该方法可以在外场地简便、有效地对寻北陀螺的与g有关的漂移项进行准确测量。通过误差补偿可以保证寻北系统长时期的工作精度。     

基于陀螺仪输出误差观测的冗余INS标定方法

冗余惯导系统陀螺仪由于确定性误差及随机误差的干扰,影响系统精度,且冗余惯导系统陀螺仪的标定过程中存在部分误差不可观测的问题。针对冗余惯导系统,设计了一种基于陀螺仪输出误差观测的标定方法。采用改进的经验模态分解算法对陀螺仪信号进行降噪处理,降低随机误差的干扰。改进冗余配置下的量测方程,以冗余陀螺仪输出误差为观测量,对陀螺仪的常值误差、标度因数及安装误差进行标定。基于四面体配置的MEMS静基座导航试验结果表明,所提出的方法与传统的零空间扩增标定方法相比,系统1 min时定位精度由70.32 m提升至24.27 m,航向角误差由22.49′提升至6.39′,验证了所提出的标定方法的有效性。     

The 7th International Conference on Fluid Mechanics May 24-27,2015,Qingdao,China

正http://www.icfm7.org First Announcement and Call for PapersThe objective of International Conference on Fluid Mechanics(ICFM)is to provide a forum for researchers to exchange new ideas and recent advances in the fields of theoretical,experimental,computational Fluid Mechanics as well as interdisciplinary subjects.It was successfully convened by the Chinese Society of Theoretical and Applied Mechanics(CSTAM)in Beijing(1987,     

INFORMATION FOR CONTRIBUTORS

Contributions： The Journal, Acta Mechanica Solida Sinica, is pleased to receive papers from engineers and scientists working in various aspects of solid mechanics. All contributions are subject to critical review prior to acceptance and publication.     

Preface

This special issue of PARTICUOLOGY is devoted to the first UK-China Particle Technology Forum taking place in Leeds, UK, on 1-3 April 2007. The forum was initiated by a number of UK and Chinese leading academics and organised by the University of Leeds in collaboration with Chinese Society of Particuology, Particle Technology Subject Group （PTSG） of the Institution of Chemical Engineers （IChemE）, Particle Characterisation Interest Group （PCIG） of the Royal Society of Chemistry （RSC） and International Fine Particle Research Institute （IFPRI）. The forum was supported financially by the Engineering and Physics Sciences Research Council （EPSRC） of United Kingdom,     

基于鲁棒滤波的捷联导引头视线角速度估计方法

针对捷联导引头无法直接获取视线角速度等信息的问题,研究了鲁棒滤波在大气层外飞行器捷联导引头视线角速度估计中的应用。为了建立非线性滤波估计模型,考虑目标视线角速度的慢变特性,采用一阶马尔科夫模型建立了状态方程;推导了视线角速度的解耦模型,并建立了量测方程;考虑到实际应用中存在系统噪声统计特性失准的问题,基于Huber-Based鲁棒滤波方法,设计了视线角速度滤波器,并完成了基于Huber-Based滤波方法和扩展卡尔曼滤波方法的数学仿真。仿真结果表明Huber-Based滤波方法的视线角、视线角速度及视线角加速度估计精度分别达到0.1140'、0.1423'/s、0.0203'/s2,而扩展卡尔曼滤波方法的视线角、视线角速度及视线角加速度估计精度仅分别为0.6577'、0.6415'/s、0.0979'/s~2。仿真结果证明了该方法可以有效地估计出相对视线角速度等信息,并且在非高斯噪声的条件下,依然可获得较高的估计精度,具有一定的鲁棒性。     

Guide for authors

正Each of the sections below provides essential information for authors.We recommend that you take the time to read them before submitting a contribution to Acta Mechanica Sinica.We hope our guide to authors may help you navigate to the appropriate section.How to prepare a submission This document provides an outline of the editorial process involved in publishing a scientific paper in Acta Mechanica     

Use specification of multiscale materials for life spanned over macro-, micro-, nano-, and pico-scale

Multiscale material intends to enhance the strength and life of mechanical systems by matching the transmitted spatiotemporal energy distribution to the constituents at the different scale, say—macro, micro, nano, and pico,—, depending on the needs. Lower scale entities are, particularly, critical to small size systems. Large structures are less sensitive to microscopic effects. Scale shifting laws will be developed for relating test data from nano-, micro-, and macro-specimens. The benefit of reinforcement at the lower scale constituents needs to be justified at the macroscopic scale. Filling the void and space in regions of high energy density is considered.Material inhomogeneity interacts with specimen size. Their combined effect is non-equilibrium. Energy exchange between the environment and specimen becomes increasingly more significant as the specimen size is reduced. Perturbation of the operational conditions can further aggravate the situation. Scale transitional functions and/or f_j/j+1 are introduced to quantify these characteristics. They are represented, respectively, by , and (f_mi/ma,f_na/mi,f_pi/na). The abbreviations pi, na, mi, and ma refer to pico, nano, micro and macro.Local damage is assumed to initiate at a small scale, grows to a larger scale, and terminate at an even larger scale. The mechanism of energy absorption and dissipation will be introduced to develop a consistent book keeping system. Compaction of mass density for constituents of size 10⁻¹², 10⁻⁹, 10⁻⁶, 10⁻³ m, will be considered. Energy dissipation at all scales must be accounted for. Dissipations at the smaller scale must not only be included but they must abide by the same physical and mathematical interpretation, in order to avoid inconsistencies when making connections with those at the larger scale where dissipations are eminent.Three fundamental Problems I, II, and III are stated. They correspond to the commonly used service conditions. Reference is made to a Representative Tip (RT), the location where energy absorption and dissipation takes place. The RT can be a crack tip or a particle. At the larger size scales, RT can refer to a region. Scale shifting of results from the very small to the very large is needed to identify the benefit of using multiscale materials.