微型UAV视觉识别系统的研究

出于军事侦察、视觉导航等特殊任务的需要,视觉识别系统一直在微型UAV系统中扮演着重要的角色。该文针对微型UAV的特点设计了一套基于机器学习的视觉识别系统。得益于Adaboost算法和层叠分类器的使用,系统具有很快的处理速度并获得了较高的正确识别率。最后,通过一套真实微型无人直升机试验平台上的实验结果,验证了这套系统的可行性。     

飞行器二维翼面整形的物理光学理论

基于物理光学下散射场计算公式，本文进行雷达波入射方向对翼面散射能量分布影响的研究及翼面几何形状改变对散射能量分布影响的研究，提出了使翼面外形主要尺寸满足ｓｉｎｃ函数零点要求或满足ｓｉｎｃ函数旁瓣要求以雷达散射截面的整形理论。     

Altemeyer replies.

Replies to commentary by J. J. Ray (see record 2007-08928-001) regarding the current author's book, Enemies of freedom: Understanding right wing authoritarianism (see record 1988-98419-000). The foremost of Ray's six criticisms is that "insofar as (I have) studied anything at all, (I have) probably studied some form of conservatism." The constructs of "right-wing authoritarianism" and "conservatism" can be defined as one wishes, and one can declare that they are the same thing. I prefer to draw several conceptual distinctions however, perhaps because one brand of "conservatism", especially visible in the United States, resents government authority. Next, Professor Ray quite correctly points out that my explanation of the development of personal authoritarianism ignored genetic possibilities. The twins-studies have caught me completely flat-footed, with my back turned, though I would find evidence for a DNA-based explanation of authoritarianism quite exciting. As for attitudes toward authorities, I suspect they do wobble some during adolescence. However, neither of the two adult studies Professor Ray cites shows "a general attitude toward authority does not exist." If anything, they suggest it does. Professor Ray says the consistency of the RWA Scale only occurs because my item selection procedures have created a distortion of the real world, a world of my own "from which the most disturbing outside information has been rigorously excluded." In fact, the covariation among items mentioning different kinds of authorities goes back to the Berkeley F Scale. Finally, Professor Ray concludes that I am studying some nonpolitical form of conservatism, because the RWA Scale gives "virtually no prediction of right-wing political preference." Data is presented to dispute this allegation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

光测力学在表征聚合物应力场中的应用

简介了光测力学的应用和基本原理,对光散射技术原理及其应用进行了说明,详细阐述了光测力学在聚合物流场应力表征中的应用,尤其是对光测力学表征挤出机口模的狭缝流场的方法和光测力学在聚合物电磁塑化挤出流场中的应用进行了详细说明,介绍了光测图象处理技术,如图像增强、模式识别等,并且展望光测力学在新型聚合物电磁动态成型机理方面作出贡献。     

Health monitoring of vibration signatures in rotorcraft wings

We propose to design and to evaluate an on-board intelligent health assessment tool for rotorcraft machines, which is capable of detecting, identifying, and accommodating expected system degradations and unanticipated catastrophic failures in rotorcraft machines under an adverse operating environment. A fuzzy-based neural network paradigm with an on-line learning algorithm is developed to perform expert advising for the ground-based maintenance crew. A hierarchical fault diagnosis architecture is advocated to fulfill the time-critical and on-board needs in different levels of structural integrity over a global operating envelope. The research objective is to experimentally demonstrate the feasibility and flexibility of the proposed health monitoring procedure through numerical simulations of bearing faults in USAF MH-53J PAVELOW helicopter transmissions. The proposed fault detection, identification and accommodation architecture is applicable to various generic rotorcraft machines. The proposed system will greatly reduce the operational and developmental costs and serve as an essential component in an autonomous control system.     

军用无人机发展趋势

论述了军用无人机的发展动力和技术保障以及发展现状，并从扩大军用无人机的应用范围和提高作战效能等方面分析其发展趋势。     

高速侦察图像数据的获取和缓冲

阐述了无人机中图象数据采集和缓冲模块的设计和实现。以FPGA为核心并综合利用FIFO和DDR—SDRAM设计了一个模块，可在200MBps数据率的情况下采集和缓冲图像数据。     

电机用轴流式风扇分析与计算

具体的详述了浆叶的物理概念，分析了叶片产生的两个力即上升力和侧阻力与攻击角的物理关系，通过旋转叶片的出风口和进风口处的气流速度分析，计算两种力和力矩关系，估算出风扇的效率和消耗的功率。根据计算出的叶片宽度，画出螺浆式风扇叶片的截面形状。     

柔性复合材料前掠翼飞机静气动弹性分析

本文作者计算分析的是柔性复合材料前掠翼概念机的静气动弹性特性。文中作者利用NASTRAN计算了单独机翼的发散速度,并重点计算和分析了该机在亚音速情况下,飞行载荷和纵向静稳定性、操纵性导数分别随马赫数和动压变化的曲线。通过对比分析可以看出:(1)相同高度下,随着马赫数的增加,刚体纵向静稳定性、操纵性导数和弹性纵向静稳定性、操纵性导数分别呈不同的变化趋势,且某些变化相差甚大;机翼剪力、弯矩和扭矩随翼展变化的曲线中,刚体部分所占的比例不断减小,弹性部分所占的比例不断增加;机翼的最大垂直挠度(在翼尖前缘处)和最大扭角(在翼尖处)略有增加。(2)相同马赫数下,随着动压的不断增加,刚体纵向静稳定性、操纵性导数保持不变,弹性纵向静稳定性、操纵性导数呈线性变化;机翼剪力、弯矩和扭矩随翼展变化的曲线中,也同样是刚体部分所占的比例不断减小,弹性部分所占的比例不断增加;机翼的最大垂直挠度(在翼尖前缘处)和最大扭角(在翼尖处)略有增加。(3)使用复合材料剪裁技术可以适当减小机翼内洗,从而提高发散速度,减小机翼前缘垂直挠度和飞行载荷中弹性部分的比例。     

多旋翼无人机脱靶量测量技术研究

针对近年来靶场对飞行器脱靶量准实时、高精度测量的迫切需求,采用系留式多旋翼无人机测量脱靶量.依据脱靶量测量的具体要求,提供了镜头、传感器等关键器件测量参数选取方法,对大视场镜头畸变误差进行了修正,提出了标志点重定位、倾角修正、高度修正等措施.在100 m高空完成了脱靶量测试.测试结果表明:在80 m内的测量误差为2 m的精度.