多星测控调度的遗传算法分析

针对多星过站冲突问题,以工程需求为导引,建立了多星测控调度模型,并采用遗传算法对其进行求解.从全局和局部搜索两种策略入手,以可用可见弧段为对象,设计了"全弧段"编码和基于协同进化的编码两种编码方式,给出了对应算法的实现流程和遗传操作算子,对两种编码方式的求解效率进行了分析.通过仿真对两种编码的求解质量与时间开销性能作了验证,由此得出了两种编码和对应搜索策略的适用范围.据此开发的系统已成功应用于航天顶层设计的辅助决策.     

基于梯度方向二值模式特征的飞机翼尖跟踪技术

研究基于视频图像分析与定位的飞机翼尖跟踪技术,为飞机地面移动提供安全保障.现有图像特征进行翼尖跟踪经常失效且计算效率低下,本文结合纹理和轮廓信息,提出以梯度方向二值模式( OG_ LBP)为特征的粒子滤波跟踪算法,降低特征维数的同时建立局部和全局的翼尖特征直方图描述,提高识别效果.同时,该算法在粒子滤波基本框架之下,结...     

无损检测技术在姿控发动机总装中的应用探析

阐述了目视检测、射线照相检测、泄漏检测等三种无损检测技术在姿控发动机上的应用情况。重点介绍了泄漏检测技术,针对发动机的结构特点、不同系统的性能要求及总装接头连接处各种密封形式在装配测试中分别采用了浸泡法、皂泡法及氦质谱简易包封积累法等不同的泄漏检测技术。经过对几种泄漏检测方法的对比分析,得出了针对不同的系统性能要求。需要采用不同的泄漏检测方法来满足设计要求的结论。     

Shadow detection for mobile robots: Features,evaluation, and datasets

ABSTRACT

Shadows have long been a challenging topic for computer vision. This challenge is made even harder when we assume that the camera is moving, as many existing shadow detection techniques require the creation and maintenance of a background model. This article explores the problem of shadow modelling from a moving viewpoint (assumed to be a robotic platform) through comparing shadow-variant and shadow-invariant image features — primarily color, texture and edge-based features. These features are then embedded in a segmentation pipeline that provides predictions on shadow status, using minimal temporal context. We also release a public dataset of shadow-related image sequences, to help other researchers further develop shadow detection methods and to enable benchmarking of techniques.     

一种新的导航星选取算法研究

在导航星表的建立过程中，由于恒星的数量太多，往往要进行筛选，通常这种选择复杂费时，而结果往往并不是最优的。本文引入了动态星等阈值分布函数，将传统星等阈值过滤算法中的静态阈值用动态星等阈值代替，建立了一种新的动态星等阈值过滤选择模式。而基于统计学习理论的支持向量机方法为求解高维非线性动态星等阈值分布函数提供了新的途径。本文讨论了这种基于支持向量机的导航星自动选择算法——回归选取算法。实验表明，用该算法所选取的导航星表，导航星数量少、分布均匀性好。同时它还能适应多种任务的导航星选取要求，具有很强的通用性。     

差分编码OQPSK调制解调器设计

OQPSK调制性能大大优于 QPSK,但由于 OQPSK调制的特殊性 ,其差分编解码相应比较复杂 ,文中对DOQPSK的差分编解码和调制解调原理进行了深入的分析 ,针对传统 DOQPSK相干解调和解码方法存在的问题 ,给出一种简单高效的改进 DOQPSK解调和解码方法。该方法不仅结构简单 ,同时消除了与 DQPSK解调相比存在的 3 d B解调损失问题 ,大大提高系统的解调性能     

海上雾霾天气下基于能见度的舰载机目视着舰风险评估方法研究

针对雾霾天气对舰载机目视着舰安全性的影响难以量化的问题,利用激光雷达在近海的能见度观测数据,反演海上雾霾天气下飞行员目视着舰的斜程能见度的状况,提出 1种基于能见度指标的目视着舰风险评估方法,将舰载机着舰过程中飞行员频繁的目测压力,转变为舰上数据测量、风险评估和应对措施等程序化工作,将定性的安全分析转变为定量的风险评估和安全指导,谋求在现有着舰控制模式下有效降低飞行员着舰压力,提升指挥引导效率,为低能见度下舰载机目视着舰训练提供理论依据和实践指导。     

基于ANP数据库的飞机起飞仿真研究

以可视化的方式全面直观的反应其航迹,来检验或者分析飞机起飞过程,为解决飞机噪声问题提供技术理论支持,利用ANP数据库,从中获取各种机型的飞行程序和性能参数,计算飞机起飞航迹及航迹上各点的推力、速度、姿态等,实现了飞机起飞过程及其航迹的三维可视化仿真。     

立体显示技术及其在航空电子系统中的应用

分析了航空电子系统对立体显示技术的需求；介绍了各种立体显示技术的基本原理，并对比了各种立体显示技术的性能特点，提出了航空电子可应用的立体显示技术设想。     

Virtual Reality-based Teleoperation with Robustness Against Modeling Errors

This article investigates virtual reality (VR)-based teleoperation with robustness against modeling errors. VR technology is an effective way to overcome the large time delay during space robot teleoperation. However, it depends highly on the accuracy of model. Model errors between the virtual and real environment exist inevitably. The existing way to deal with the problem is by means of either model matching or robot compliance control. As distinct from the existing methods, this article tries to combine model matching and robot compliance control. On one hand, the status of the virtual robot is corrected by using the position sensor data from robot joints before and during teleoperation, and the pose of the virtually manipulated object is obtained with visual recognition technology. On the other hand, compliance control algorithms of impedance control based on joint torque sensors and hybrid position/force control based on a wrist sensor have been executed in order to eliminate the small sustaining model errors. A VR-based teleoperation system of satellite on-orbit self-serving is built up. In order to verify the proposed method, an experiment deploying the solar panel troubled by malfunction is carried out through teleoperation. It shows that the large model errors are removed with the model matching method and the adopted compliance control is robust against the remaining small model errors.