GPS实时定姿系统的设计与实现

以GPS OEM板为基本硬件,在自行研制GPS实时定姿软件的基础上,搭建了GPS实时定姿系统。该系统硬件结构简单,成本低廉。定姿软件解决了数据接收、解码、同步,模糊数快速计算,动态检校等关键技术。经多次静态、动态试验验证,系统运行稳定,动态跟踪性能良好。基线长度为1.2m时,定姿精度优于0.3°,可单独用于系统的导航,或作为系统导航设备的校准装置,具有很好的应用价值。     

星载GPS低轨卫星几何法精密定轨研究

本文讨论了星载ＧＰＳ接收机为单频情形的代轨卫星几何法定轨,包括载波一相对定轨法和动态网定轨法,并利用Ｔｏｐｅｘ／Ｐｏｓｅｉｄｏｎ卫星星载ＧＰＳ实测数据中Ｌ１载波相位观测值进行验证,结果表明,载波相位相对定轨精度与地面基准站的观测质量有关,其三轨道位置精度为分米级;载波相位动态风定轨精度介于各基准站皮相位相对定轨之间,它相当于在各基准站相对定轨之间加权均衡,而且提高了定轨的可靠性。     

态势感知的概念与发展综述及微纳仿生态势感知系统的顶层设计

简要综述西方科技强国的态势感知概念、态势感知系统研发现状与应用、主要研发计划,总结其经验与教训,分析中国发展态势感知技术的迫切性与突破点.提供解决方案,介绍科研课题"微纳仿生空间态势感知器"中的态势感知概念、包括需求分析、模型设计、概要设计、应用设计的系统顶层设计内容.态势是指生物或系统对其内部状态和外部环境的"综合印象",包括自身状况和变化趋势、外部环境呈现出的某种状态和形势、发展趋势等.具有类似生物感知能力的态势感知器需要对自身状况、外界环境的多种物理量进行综合监测,其目的在于获取自身和环境的全面的、系统的信息.应用成熟的微纳米技术成果,以仿生学为主要理论导引,采用快速原型法设计开发基于微纳米技术和仿生学的态势感知器,可以广泛应用在太空、军事、环境保护、工业、消费电子等领域.     

GPS时差数据采集器的研制

介绍一种用于ＧＰＳ定时接收机自动数据采集的专用装置，该装置利用单片机技术实现ＧＰＳ定时接收机的时差有关数据按程序进行采集与存贮。对电路设计和软件设计作了全面说明。     

基于OMNeT++的卫星姿态控制系统仿真

针对三轴稳定卫星的姿态控制系统,在离散事件仿真平台OMNeT 的基础上,建立了一个以星敏感器和陀螺为敏感器,反作用飞轮为执行机构的闭环控制仿真系统。采用双矢量定姿算法和PID控制算法,对该卫星在对地定向模式下的控制精度进行了仿真。仿真结果清晰地反映了星敏感器和反作用飞轮输出延时对控制精度的影响。整个仿真系统符合面向对象和模块化的程序设计理念,并实现了仿真程序的重用。     

基于专家系统CLIPS的故障诊断研究

利用CLIPS建立专家系统知识库及推理机,通过CLIPS嵌入式编程,设计并实现了飞机燃油故障诊断专家系统,并经过仿真验证,该系统很好地发挥了专家系统的智能性,能够快速准确地诊断出故障。     

A320飞机轮胎压力指示系统一条假故障信息的触发分析

本文以A320飞机轮胎压力指示系统TPIS一条假故障信息的经常性触发为切入点,着重于故障集中显示系统CFDS关于1型系统故障／警告信息的触发原理分析,揭示发动机地面试车有效航班号输入的必要性和这条假故障信息的触发原因。     

民用飞机发动机监测方法研究

对民用飞机发动机状态监测和故障诊断方法进行了研究,提出了一种能够实时反映零件故障信息的油液在线静电监测方法,设计并搭建了一套静电监测系统及实验平台,开展了循环润滑条件下销盘滑动摩擦磨损实验,使用自制的油液静电传感器对油路中磨粒进行监测。实验结果表明油液静电传感器能够监测到金属材料荷电颗粒,感应电压幅值与磨粒大小具有相关性,感应电压波形与磨粒荷电特性有关,验证了静电传感器在线监测的有效性,为判断故障提供了进一步的依据。     

无线传感器网络性能评价系统设计

针对无线传感器网络的性能评价指标多样、缺乏统一标准的问题,设计了一种无线传感器网络性能评价系统。该系统包括频谱分析子系统、电流采集子系统和无线传感器监测子系统,能够对无线传感器网络的空中频谱特征、网络中节点的工作电流特征、网络丢包和吞吐量特性进行采集、统计与分析,实现对无线传感器网络的性能评价。     

Time synchronization of new-generation BDS satellites using inter-satellite link measurements

Autonomous satellite navigation is based on the ability of a Global Navigation Satellite System (GNSS), such as Beidou, to estimate orbits and clock parameters onboard satellites using Inter-Satellite Link (ISL) measurements instead of tracking data from a ground monitoring network. This paper focuses on the time synchronization of new-generation Beidou Navigation Satellite System (BDS) satellites equipped with an ISL payload. Two modes of Ka-band ISL measurements, Time Division Multiple Access (TDMA) mode and the continuous link mode, were used onboard these BDS satellites. Using a mathematical formulation for each measurement mode along with a derivation of the satellite clock offsets, geometric ranges from the dual one-way measurements were introduced. Then, pseudoranges and clock offsets were evaluated for the new-generation BDS satellites. The evaluation shows that the ranging accuracies of TDMA ISL and the continuous link are approximately 4?cm and 1?cm (root mean square, RMS), respectively. Both lead to ISL clock offset residuals of less than 0.3?ns (RMS). For further validation, time synchronization between these satellites to a ground control station keeping the systematic time in BDT was conducted using L-band Two-way Satellite Time Frequency Transfer (TWSTFT). System errors in the ISL measurements were calibrated by comparing the derived clock offsets with the TWSTFT. The standard deviations of the estimated ISL system errors are less than 0.3?ns, and the calibrated ISL clock parameters are consistent with that of the L-band TWSTFT. For the regional BDS network, the addition of ISL measurements for medium orbit (MEO) BDS satellites increased the clock tracking coverage by more than 40% for each orbital revolution. As a result, the clock predicting error for the satellite M1S was improved from 3.59 to 0.86?ns (RMS), and the predicting error of the satellite M2S was improved from 1.94 to 0.57?ns (RMS), which is a significant improvement by a factor of 3–4.