一种智能防错的辅助人工作业系统开发与应用

针对航空制造业人工装配出现的操作易出错、效率低、培训成本高、质量不稳定等问题,开发了一种辅助人工作业系统,通过投影指示、体感摄像、触摸显示等方式来辅助人员装配.同时对于作业引导、零件选取、螺钉拧紧等易出现问题进行了智能防错设计.通过一种航空机载机电产品的手工装配工程应用,实现了装配过程的辅助引导监控,提高人工装配的质量...     

面向航天应用的液态金属相变传热性能研究

为探究液态金属相变材料的适用范围，本文使用数值模拟手段，比较分析了以镓为代表的低熔点金属与以正十八烷为代表的石蜡类相变材料之间的传热性能。结果表明，镓更适用于应对瞬时高热流冲击，即高热流、短时间工作的电子设备散热；而正十八烷适用于低热流、较长时间工作的电子设备控温。此外，单位体积相变材料，镓模块的热控时间长于正十八烷模块；单位质量相变材料，镓模块在短时间内占优，长时间内正十八烷模块占优。针对潜在应用场景进行分析，表明了液态金属相变材料可用于航天天线TR组件和激光器芯片控温。     

基于FR4的多自由度电磁式扫描光栅微镜结构设计

本文面向低成本、高可靠、便携式光谱分析检测设备的需要，提出了一种基于FR4（Flame Retardant，阻燃等级为UL94V-O的板材，4表示树脂为环氧树脂、增强材料为玻璃纤维布）复合材料的多自由度电磁驱动微型集成扫描光栅微镜新结构。通过多自由度结构设计，有效提升了微镜转动角度。建立了器件有限元仿真模型，开展了静力学、模态及谐响应分析。有限元分析结果表明：微镜能够在设定谐振模态下工作，其微镜与驱动线圈的位移比值为1.795，为大转角电磁式微型集成扫描光栅微镜设计提供了一种新方法。     

腿臂融合型在轨装配机器人运动建模与步态规划

针对目前机器人在轨装配存在的作业效率低、空间操作受限、环境感知不完全等问题，提出一种腿臂融合型在轨装配机器人。首先，使用D-H法建立了腿臂融合型装配机器人运动学模型，并对其单个腿部进行正逆运动学分析，得到单个腿各个关节角和足端之间的运动关系；其次，分析了腿臂融合型装配机器人的行走步态和装配步态，行走步态中分析了二步态和三步态，装配步态中分析了单臂装配和双臂装配，使机器人达到平稳的行走和装配；最后，基于ROS(robot operating system)搭建仿真平台并对行走步态进行了仿真验证，结果表明提出的方法能够有效用于该机器人的行走。     

某扭力管万向节组件及支撑轴承的正弦振动疲劳研究

本文建立C919某扭力管万向节组件及支撑轴承的有限元模型，对其进行模态分析及正弦分析，推导了正弦振动下的疲劳寿命计算公式并预估了模型的寿命，通过模态试验验证了模型的正确性，通过正弦试验验证了疲劳寿命计算的正确性。该疲劳寿命计算方法可用来预估相关模型的正弦振动疲劳寿命。     

卫星大部件二维转台装配工艺方法

为了满足某卫星大部件二维转台在地面重力状态装配后，保证其在轨解锁前精度一致性，提出了二维转台装配工艺优化方法。首先通过模拟载荷配重试验，探索转台星上接口重力下变化规律，保证结构板组合加工偏差，优化卫星层板组合加工工艺方法;其次分析二维转台机构变形，采用卸载装星工装，并对二维转台卸载装配前后关键变形进行精测对比。二维转台通过模拟试验和卸载装配后，保证了地面重力压紧状态和卸载状态下装配精度均在设计指标内，满足卫星二维转台装配要求。通过模拟试验确定结构加工公差余量，在进行卸载装配时，对卸载前后精度精测对比，是卫星大部件载荷装配工艺的正确方法。     

Enhancement on parallel unstructured overset grid method for complex aerospace engineering applications

In the present study, an efficient overset grid method by means of parallel implicit hole-cutting is proposed for the sake of simulating unsteady flows in aerospace engineering involving multiple bodies in relative movement. In view of the degraded computational efficiency and robustness for conventional overset grid assembly, several innovative techniques are developed within the overset grid assembly process, viz., a bookkeeping alternative digital tree method to speed up the donor-cell search...     

基于机器视觉的搅拌摩擦焊缝装配质量评测方法

搅拌摩擦焊常采用无坡口焊缝,焊缝装配质量对搅拌摩擦焊装配质量影响较大,通过焊缝的特征,可以对搅拌摩擦焊缝的装配质量进行评判。线结构光是提取焊缝特征的常用手段,基于结构光传感器扫描获得的焊缝轮廓信息多通过离散的点进行表示,如何高效地从轮廓点中提取焊缝轮廓信息,是焊缝特征识别的新挑战。本文提出一种基于机器视觉的焊缝装配质量评测方法,将离散的轮廓点转换为位图,通过抗锯齿算法提高轮廓直线特征的识别可靠性,并计算对应焊缝的装配质量信息,进而实现对整条焊缝的装配质量的量化评价。与传统的离散点拟合方法相比,本方法具有较为明显的效率优势。     

六西格玛在军用飞机发动机总装质量控制中的应用

国内某军用飞机主机厂C 发动机装机后存在间隙尺寸超差、装机一次合格率低的问题，为了解决该问题，引入六西格玛质量管理模式的DMAIC 方法对发动机装机流程进行研究。运用多元回归分析、机理分析等确定影响间隙尺寸的关键因子及其影响程度，采用线性拟合得出关键因子最优参数范围，并制定详细控制计划。通过对控制图进行分析，发现改善后的间隙尺寸处于工序稳定状态，发动机装机一次合格率由改善前的65.2% 提升至95%，表明基于六西格玛DMAIC 方法的质量控制对减小生产流程变异，提高生产效率有积极作用。     

Quantitative contribution of climate change and anthropological activities to vegetation carbon storage in the Dongting Lake basin in the last two decades

The Dongting Lake Basin is an important hydrological regulation and flood storage area in the Yangtze River Basin, which plays an important role in maintaining regional ecological security. The watershed vegetation and its carbon sequestration capacity have changed dramatically due to climate change and human activities in the last two decades. In this paper, the monthly and annual vegetation net primary productivity (NPP) of the Dongting Lake basin during 2000 to 2020 was firstly estimated using the improved Carnegie-Ames-Stanford Approach (CASA) model. Then the multi-year NPP change trend and its significance were analyzed based on Theil-Sen median and Mann-Kendall method. Subsequently, the Hurst index was used to simulate the vegetation NPP persistence in the study area. Finally, the driving mechanisms of vegetation NPP changes in the study area were explored using partial correlation coefficients and residual analysis. The results demonstrated that: 1) The annual average NPP in the basin showed a fluctuating and increasing trend from 273.54 to 718.30 g C/m²·yr¹ during 2000 to 2020, and except for autumn, all seasons (spring, summer, winter) and annual NPP series showed an upward trend. The spatial distribution of vegetation NPP is characterized by an asymmetrical horseshoe shape in general, with high values in the west, south and east parts, and low values in the Lake area; 2) During the study years, about 84.38 % of the basin area showed a significant and extremely significant increase of NPP; 3) The future trend of vegetation NPP in the basin shows that the area of decrease (22.79 %) is more than the area of increase (11.35 %). The Chang-Zhu-Tan urban agglomeration will generally show a continuous and extremely significant reduction trend, while parts of Dongting Lake will show a continuous and extremely significant increase trend; 4) The correlation between solar radiation and NPP is stronger than the other two meteorological factors (precipitation and temperature). Temperature has a significant inhibitory effect on NPP, solar radiation has a significant promoting effect on NPP, and the effect of precipitation on NPP was relatively complicated. The relative importance of meteorological factors on vegetation NPP was ranked as follows: solar radiation > precipitation > temperature. The impacts of both climate change and human activities on NPP changes showed great spatial variability, and the positive contributions (89.81 % for climate change and 82.87 % for human activities) were both greater than the negative contributions.