Distributed UAV swarm based on spatial grid model

Unmanned Aerial Vehicle (UAV) swarm has become the inevitable trend of development, which will enjoy broad prospects to be applied in the future. However, the change of UAV application mode will certainly bring new technical challenges in the flight management, environmental perception, collaborative control as well as other fields. This paper considers that it can be an effective solution to realize the unified management of spatial information on the UAV platform by adopting the spatial grid model represented by the GeoSOT-3D, and to reduce the workload of flight management, airborne environmental perception, and ranging in the neighborhood through the association and query of all spatial grid data.     

Gravity field models from kinematic orbits of CHAMP,GRACE and GOCE satellites

The aim of our work is to generate Earth’s gravity field models from GPS positions of low Earth orbiters. Our inversion method is based on Newton’s second law, which relates the observed acceleration of the satellite with forces acting on it. The observed acceleration is obtained as numerical second derivative of kinematic positions. Observation equations are formulated using the gradient of the spherical harmonic expansion of the geopotential. Other forces are either modelled (lunisolar perturbations, tides) or provided by onboard measurements (nongravitational perturbations). From this linear regression model the geopotential harmonic coefficients are obtained.     

Methods to determine stress profile in ALT based on theoretical life models

With the recent products being more reliable,engineers cannot obtain enough failure or degradation information through the design period and even the product lifetime,therefore,accelerated life test(ALT)has become the most popular way to quantify the life characteristics of products.Test design is the most essential topic,such as testing duration,stress profile,data inference,etc.In this paper,a method and procedure based on theoretical life models is proposed to determine the accelerated stress profile.Firstly,the method for theoretical life calculation is put forward based on the main failure mechanism analysis and the theoretical life models.Secondly,the method is provided to determine the accelerated stress profile,including the method to determine the accelerated stress types and the stress range on the basis of the main failure mechanism analysis,the method to determine the acceleration factor and the accelerated stress level based on life quantitative calculation models,and the collaborative analysis method of the accelerated test time while taking the multiple failure mechanisms into consideration.Lastly,the actuator is taken as an example to describe the procedure of the method and the engineering applicability and the validity are verified.     

套索驱动柔性细长机器人视觉运动系统建模与分析

运动和感官进程之间紧密的相互作用,是生物视觉系统进行目标距离估计和观察周围环境的重要特征.为了建立适合套索驱动柔性细长机器人视觉系统模型,分析了通过生物眼球运动策略,以获得准确距离估计和环境信息的机理.此外,探讨了在摄像机系统中通过模拟生物眼球运动策略进行距离估计和周围环境观察的可能性,以及通过纯机械方式,模拟基于Listing法则眼球扫视运动的可能性.最后,提出Listing平面应是套索驱动机器人视觉测量和空间姿态控制结合点的观点.     

双马来酰亚胺树脂化学流变特性研究

在粘度实验的基础上 ,根据双阿累尼乌斯方程对用于 RTM工艺的双马来酰亚胺树脂体系的化学流变特性进行了研究 ,建立了树脂体系的流变模型。通过 DSC热分析实验研究树脂体系的固化反应规律 ,验证了双阿累尼乌斯模型。研究表明 ,模型与实验结果具有良好的一致性。模型可揭示树脂体系在不同工艺条件下的粘度变化规律 ,定量预报 RTM工艺树脂的低粘度平台工艺窗口 ,为合理制定 RTM工艺参数、保证产品质量和实现工艺参数的全局优化提供必要的科学依据     

CAD／CAE／CAM集成系统的数据结构研究与实现

数据结构设计是ＣＡＤ／ＣＡＥ／ＣＡＭ集成系统的关键技术，数据结构的好坏直接影响集成系统的性能。本文以几何模型、绘图模型及分析模型的数据结构为例，论述了集成系统中各模块的数据结构的基本内容及其相互关系，提出了一种多模型下分模型管理的统一数据结构的设计思想，其最大特点是用统一的数据库进行管理，各模型间数据的相互利用是直接引用，从而保证数据的完整性和一致性，减少数据冗度。并以局部数据结构为例，说明了数据     

基于灰色局势决策的航空弹药库选址问题研究

以弹药库选址问题为事件,以备选库址作为对策构成局势,采用局势决策建立数学模型,以寻找最优库址为目标,对不同量纲的目标量值以效果测度统一计量,并通过最优效果测度确定最优局势,对四个备选方案的综合优劣状况进行排序,最后得到最优的选址方案,所得结论具有很强的客观性和实用性。     

集模式分散滤波及其应用

把集模式的思想用到了分散滤波中，并针对有关文献中加权因子的选取存在的必须凭经验进行的问题、对集模式分散滤波的加权因子的确定提供了一种方法，即利用状态量的误差协方差的特征值平方来确定加权因子。利用本文介绍的集模式分散滤波方法对INS/GPS/TAN组合导航系统进行了仿真。仿真结果表明，本文介绍的滤波方法具有较高的精度，因而不失为一种可行的滤波方法。     

流化床干燥过程数学模拟的研究

本文通过对流化床干燥过程的机理分析，将干燥过程分为预热阶段、恒速干燥阶段、降速干燥阶段，提出模型的简化条件，建立3个阶段的数学模型，用解析或数值方法求解，并应用于聚氯乙烯的干燥，模拟出干燥特性曲线，其结果表明该模型与实际基本相符。     

数学真理是相对真理--从"第二次数学危机"谈起

文中指出根据唯物辩证法中关于一切真理都是相对真理的观点，数学真理当然也是相对真理。这是是解决“第二次数学危机”的突破口，应该接受欧拉和马克思的意见，承认求导数的运算中出现的0／0的结果是正确的。还分析了数学中的非欧几何、集合论、布尔代数以及概率算术的一些情况，说明数学真理确实是相对真理。文中还指出．由于数学公理化体系的基础即数学公理通常是归纳出来的，所以也是相对真理。