气动计算软件集成系统中的远程控制

随着我国航空航天技术的飞速发展,气动计算软件集成技术日趋成熟,但用户在并行计算中需要手动输入的操作较多。鉴于此,通过编程开发了基于TCP／IP协议的FTP客户端应用程序,实现了对网格文件的信息采集、过滤并将其和参数、脚本文件等批量自动上传的功能。根据批处理文件中的命令,调用Windows平台自带的客户端Telnet,向远程集群管理节点发出命令,远程启动服务器集群的并行计算任务。最后,在客户端实现了远程控制服务器集群上的计算流体力学软件Fluent进行并行计算。结果表明：使用该远程控制系统能够减少用户输入操作,提高计算效率,保证数据的实时更新。     

基于滑模反演控制的稳定平台齿隙非线性补偿

针对航空遥感惯性稳定平台中齿隙非线性带来的不稳定问题,结合反演控制和滑模控制的优点,在传统反演控制的每一步迭代过程引入与齿轮运动状态相关的基于连续饱和函数的动态滑模面,设计了相应的滑模反演控制器。在保证了系统误差快速收敛的同时,抑制了反演过程中的误差积累,实现了系统非线性误差精确补偿。仿真实验结果表明,与传统反演控制相比,滑模反演控制显著降低了齿隙非线性对系统动态性能的影响,有效提高了系统对期望角位置、角速度的跟踪性能。     

嵌入式远程监测系统的硬件设计

采用单片机和微控制器的监测系统己得到广泛的应用,但这些系统在数据处理、网络通讯等方面能力有限,无法适应远程实时监测的要求.采用新型32位嵌入式CPU进行了一种远程监测嵌入式系统解决方案的硬件设计.系统实现了8通道模拟信号采集,具有功耗低、体积小、集成度高等特点.采用SD卡存储技术、以太网技术以及USB技术,提高了系统智能化和网络化程度.系统可以实时地监测设备状态,对状态信息进行分析与保存,并可以通过网络提供设备运行状态信息.     

航天光学采样成像系统MTF的优化设计与MTFC

简要介绍了成像链、成像系统和遥感系统的概念;对像质和像质差异的表征和度量、成像系统性能的表征等予以说明;重点探讨航天光学采样成像系统MTF的优化设计与MTFC问题,并给出讨论结果。     

航天光学遥感器光学装调技术现状与展望

航天光学遥感器工作于太空中,长期恶劣的空间环境及短暂发射入轨时的状态对光学系统的设计与装调提出了苛刻的要求,确保光学系统在轨像质优异是航天光学遥感器研制的关键技术.文章结合国际上航天光学遥感器的发展需求对光学系统装调技术及发展现状进行了分析、总结,提出了中国后续航天光学遥感器装调与测试技术的突破方向.     

Earth observation from space – The issue of environmental sustainability

Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following:1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions.2. Space launches are benign with respect to environmental impacts.3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change.4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space.5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products.At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of the data acquisition step, which is at the very beginning of the information stream leading to decision and action, will enhance coherence in the information stream and strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions in the context of sustainable management of Earth's resources. Taking each assumption in turn, we find the following:(1) Space debris may limit access to Low Earth Orbit over the next decades.(2) Relatively speaking, given that they're rare event, space launches may be benign, but study is merited on upper stratospheric and exospheric layers given the chemical activity associated with rocket combustion by-products.(3) Minimization of Type II error should be considered in situations where minimization of Type I error greatly hampers or precludes our ability to correct the environmental condition being studied.(4) In certain situations, airborne collects may be less expensive and more environmentally benign, and comparative studies should be done to determine which path is wisest.(5) International cooperation and data sharing will reduce instrument and launch costs and mission redundancy. Given fiscal concerns of most of the major space agencies – e.g. NASA, ESA, CNES – it seems prudent to combine resources.     

基于EJB的多层分布式系统模型的研究与应用

现今应用程序体系结构已发展到分布式计算模型,本文通过对分布式中间件EJB(EnterpriseJavaBeans)的体系结构和技术规范的研究和分析,深入探讨了EJB体系结构的相关概念以及基于EJB的多层分布式企业应用开发的工作原理,论述了EJB是构建企业分布式应用的一种服务器端开发模型,并以网上购物为例为构建企业多层应用提供了一种开发方法。     

飞机MIL-STD-1553B总线的测试系统

从MIL -STD - 1 5 5 3B总线在综合航电系统的作用入手 ,分析了国内外总线测试系统的功能和特点 ,并针对将来飞机航电系统设计及发展的方向 ,提出了一种新型的MIL -STD - 1 5 5 3B总线测试系统的设计思想     

远程多路视频信号无线传输采集系统设计

设计了一种远程多路视频信号传输采集系统,通过模拟信号远程无线传输的方式将摄像头获得的视频信息传输到监控计算机,由计算机上的图像采集卡进行采集,由监控软件进行多路信号的显示,该系统在多机器人系统中取得了良好的应用效果。     

头盔伺服系统的主动柔顺控制

 对头盔伺服系统(HMDPM)主动柔顺控制策略的主要内容——轨迹规划和控制方法进行了研究。首先,采用基于力反馈和滑动杆动力学模型的头部运动预测法进行轨迹规划,该方法利用并联机构(PM)分支杆长与运动平台位姿间的映射关系,通过力反馈信息和6-3UPS并联机构滑动杆动力学模型对头部运动进行预测,为头盔伺服系统的位置控制提供期望轨迹;然后,基于头盔伺服系统的动力学模型对系统的惯性项和非线性项进行了计算,设计了惯性项和非线性项补偿控制器,在进行头部运动跟踪的同时,实现了头盔显示器与头部间接触力的控制;最后,采用SimMechanics模块建立了HMDPM—人交互模型,并进行了相关验证实验。仿真结果表明,基于力反馈和滑动副滑动杆动力学模型的头部运动预测法能实时地、较为准确地预测出头部运动位置;基于动力学模型的惯性和非线性项补偿控制器不仅可以较为准确地跟踪头部运动,而且还能有效地减小头盔显示器与头部间的接触力,降低执行机构的刚度、减少系统摩擦力等非线性因素对使用者的干扰。