MEMS压差传感器在小型无人机空速测量中的应用

介绍了一种基于MEMS压差传感器和数字信号处理器(DSP)的小型无人机空速测量系统的实现方法.根据实际需求对压差传感器进行了温度补偿,并采用最小二乘法消除器件和电路的非线性;经实验测试,空速在13～50 m/s范围内,该系统的测量精度在±3％以内.该空速测量系统具有体积小、重量轻、功耗低、工作可靠等优点.     

基于MS5534的无人机用高度传感器

在无人机的飞行控制中，飞行高度是重要的控制参数。基于数字压力传感器NS5534研制的高度传感器，对大气压力进行了温度补偿，用软件滤波兼顾了数据稳定性和频率响应，采用气压-高度的分段非线性拟合保证了精度，并结合飞控系统设计了通信接口。该高度传感器具有体积小、质量轻、数据稳定、响应快的优点，特别适合无人机的使用，经某型号无人机飞行试验，完全满足飞行控制系统的要求。     

小型无人机地面监控系统软件设计与实现

针对小型无人机飞行监测和控制的任务需求,设计了一种地面监控系统软件.系统实现了导航参数实时获取、飞行控制参数在线调整、航迹规划与回显、数据存储及分析等功能,并为超视距飞行提供了有利保障.经大量完全自主飞行实验结果表明,所设计的监控系统软件不仅能够满足小型无人机下行信道传输数据量大的监测要求,而且可以确保上行信道控制参数高精度、高可靠性的要求.     

基于路线优化的关口表数据无人机自主采集研究

为了实现关口表数据采集的自动化和高效性,现提出一种基于路线优化的关口表数据无人机自主采集系统。考虑到城镇和乡村地区建筑物、地形、路线的影响,采用蚁群算法对无人机飞行路线进行整体优化。安装有RFID读写器的无人机在GPS网络和RFID应用系统的共同作用下,完成由大范围到小区域的精准定位,在变电站表面悬停并利用电子标签和读写器进行数据采集和传输。可实现关口表数据的自动化采集和智能化控制管理,大大节约时间和费用成本,降低抄表的难度。     

六足机器人协同无人机大气数据分析系统

针对核爆现场、山地沟壑、荒漠、草原、丛林等非结构复杂环境的大气数据实时监测,提出了一种基于六足机器人和无人机的协同通信采集分析系统。建立六足机器人行走分析系统、无人机数据采集系统及多机无线通信系统三位一体的硬件软件平台。采用小型旋翼无人机搭载STM32微控制器处理温湿度传感器、PM2.5传感器、氮硫氧化物传感器实时采集的大气数据,并通过基于GFSK调制的无线数传模块传输给地面六足机器人上位机平台,建立API(空气污染指数)Simulink模型,综合已采集的大气污染指标浓度,计算得到该地区某段时间内的空气污染指数。经实验验证后,整体系统在满足功能条件下安全可靠,与常规监测手段比较,环境适应性更强,监测半径大幅上涨。解决了非结构特殊环境大气数据监测的固有缺点,一定程度改进了常规大气数据监测手段,为特殊非结构环境大气污染状况监测提供了帮助。     

无人机飞行控制系统软件故障注入方法研究

本文介绍了应用软件故障注入技术实现无人机飞行控制系统可靠性的评测方法。通过在无人机飞行控制计算机的外部数据总线上截获飞行参数,模拟无人机系统的硬件故障,构建故障模型并实现故障注入过程。实际应用表明该系统可以有效评估无人机飞行控制系统的故障检测、系统可靠性和容错能力。     

航天科工自主研发雀鹰无人机飞行试验在西藏高原获成功

9月11日,中国航天科工三院自主研发的雀鹰无人机在西藏高原成功进行了飞行试验,对全机系统和机载设备的高原适应性进行了验证,创造了三院小型无人机的起飞高度、升限等各项纪录,并与具体使用单位建立了联系,为该型无人机在高海拔地区推广使用奠定了基础。雀鹰无人机研发团队克服高原反应等各种不利条件,在短短12天内,顺利完成海拔3700m和海拔4700m的两次试飞,无人机稳定飞行在海拔5050m,获取了宝贵的飞行试验参数。经分析,雀鹰无人机还有余量,升限可以达     

小型无人机大气数据计算机的研究与设计

分析无人机基本大气参数的计算原理，针对小型无人机特点设计了一种低功耗、小型化、低成本的大气数据计算机。实验表明，该大气数据计算机反应快、误差小、功耗低、并降低了大气数据计算机的生产成本，对扩大大气数据计算机的应用范围具有一定的推动作用。     

基于视觉的小型四旋翼无人机自主飞行控制

提出为实现小型四旋翼无人机自主飞行控制,设计一种基于视觉的飞行控制方法,并搭建嵌入式控制架构飞行试验平台。在控制过程中,光流信息与姿态角信息进行融合用于估计无人机水平位置信息,利用获取到的水平位置信息作为内外环结构的比例微分积分(Proportion integration differentiation,PID)控制器外环反馈信息。不同于传统的基于地面站的控制架构试验平台,该飞行系统中采用了一个嵌入式控制架构的试验平台。该平台依靠机载嵌入计算机进行光流计算、运动状态估计,并采用机载飞行控制器执行控制算法。这种嵌入式控制架构工程实现难度高,但更利于实现四旋翼无人机的全自主飞行控制。试验结果表明,提出的设计方法取得了较好全自主飞行控制效果。     

某型无人机多传感器数据融合设计要求

无人机在程控飞行状态下要实现安全飞行,其飞控系统必须要具有高精度的飞行参数。传感器是其采集数据的重要途径,但单个传感器往往不能提高数据精度,为程控飞行带来不确定性。本文研究MSDF理论,并推导出符合高度及姿态角精度要求的计算公式,梳理应用该技术的方法和算法,进而对引入融合技术后的通道进行分析。通过MSDF技术,在不改变原结构的基础上,进一步提高飞控系统的可靠性。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.