基于MAS的实时诊断技术在电源系统中的应用研究

为了提高卫星这类大规模复杂系统的诊断速度和精度,提出了一种基于MAS 的卫星电源系统分布式诊断框架。框架的核心部分是两类诊断Agent：一类是自适应全局Age nt,负责全局诊断,采用多信号模型的诊断方法;另一类是子系统驻留Agent,负责局部诊 断,采用参数估计的诊断策略,并引入Box\|Jenkins的建模方法。通过通讯Agent和电源专 家Agent实现多Agent间协调工作。在电源系统中的应用表明,两种诊断Agent间优势互补, 提高了诊断效率,并能准确地给出诊断结果。
     

基于加速度分析的星载SAR-GMTI运动目标参数估计

针对具有加速度的地面快速运动目标对合成孔径雷达成像和参数估计带来的影响,提出了一种基于重聚焦的三通道运动目标检测方法.通过分析包含加速度的运动目标回波模型,使用广义二阶Keystone变换对杂波抑制后的通道数据进行距离弯曲校正,时频分析构造二次相位补偿函数校正剩余距离走动,并结合方位向傅立叶变换对运动目标进行聚焦成像.最后采用干涉处理技术求解运动目标参数矢量,完成目标的定位.仿真结果验证了该运动目标参数估计方法的有效性.     

用于飞行器横滚稳定控制的组合陀螺舵研究

在传统单转子陀螺舵的基础上,通过仿真分析和虚拟试验,对陀螺转子数量、结构参数、组合形式和空间布局等进行了多学科优化设计,形成了一系列多转子组合陀螺舵,突破了传统单转子陀螺舵控制能力较小、应用范围受限的现状,提高了其对飞行器横滚稳定控制的能力;针对几种典型飞行器的约束条件,通过组合陀螺舵的设计应用,使其横滚衰减因子达到0.002以上,具有良好的横滚稳定性,有助于推动组合陀螺舵在航天飞行器领域的应用和创新。     

Control and utilization of range-dependent beampattern with waveform diverse array radars

The transmit antenna beampattern of the phased array radar is only a function of angle, limiting its ability to discriminate the targets from the same direction. Recently, the waveform diverse array radars expand the angle-dependent beampattern to an angle-time-range-dependent three-dimensional function by modulating the frequencies/time delays/phases across different transmit antenna elements. In this respect, extra Degrees-of-Freedom (DOFs) in the range domain are achieved, which opens up an innovative way to fulfil the tasks with enhanced system performance by jointly using the angle and range information. This paper summaries the developments of waveform diverse radars, including the Frequency Diverse Array (FDA), the Space-Time-Circulating-Array (STCA), and the Element-Pulse-Coding (EPC) frameworks, with emphasis on the analysis of the range-dependent beampattern from the basic properties upon how it is controlled. Moreover, the most recent advances of utilizing such a range-dependent beampattern in target detection, parameter estimation and identifiability, clutter suppression, jammer suppression and Synthetic Aperture Radar (SAR) imaging are discussed.     

三维编织机锭子,轨道及锭槽结构尺寸的选择

分析了三维四步法编织机锭子运动的特点，提出了锭子与锭槽尺寸公差的选择原则；讨论了各种误差存在时，锭子可能窜入相邻轨道锭槽的情况，提出了防止锭子卡死或发生其它不良情况的结构措施，并举例进行了结构尺寸的选择。     

一种MEMS陀螺仪零偏建模与估计方法

针对MEMS陀螺仪零偏随时间变化的问题,提出了一种MEMS陀螺仪的零偏建模与估计方法.通过分析静态条件下陀螺仪零偏变化的影响因素,建立了陀螺仪零偏和温度之间的差分方程模型.采用系统辨识的方法,给出了系统模型的参数辨识流程.基于最小二乘法,实现了模型参数的辨识.设计了测试验证试验,基于陀螺仪的零偏样本特性建立了三阶差分方程,并进行了参数辨识和模型验证,结果表明该模型可以有效地估计陀螺仪的零偏.     

一种航天测控设备技术状态快速自动建立方法

根据传统测控设备技术状态的建立方法,每个参数宏对应唯一一种技术状态,一个测控任务可能需要装订上百个甚至上千个参数宏,当航天器技术状态发生变化时,还需要人工操作更换参数宏,这为测控设备技术状态的建立、设备操作、应急处理和技术状态管理带来了很大困难.提出了一种测控设备技术状态快速自动建立方法,设计了支持多测控体制、多工作频...     

Performance improvement of licklider transmission protocol in complex deep space networks based on parameter optimization

A reasonable parameter configuration helps improve the data transmission performance of the Licklider Transmission Protocol (LTP). Previous research has focused mainly on parameter optimization for LTP in simplified scenarios with one to two hops or multihop scenarios with a custody mechanism of the Bundle Protocol (BP). However, the research results are not applicable to communications in Complex Deep Space Networks (CDSNs) without the custody mechanism of BP that are more suitable for deep space communications with LTP. In this paper, we propose a model of file delivery time for LTP in CDSNs. Based on the model, we propose a Parameter Optimization Design Algorithm for LTP (LTP-PODA) of configuring reasonable parameters for LTP. The results show that the accuracy of the proposed model is at least 6.47% higher than that of the previously established models based on simple scenarios, and the proposed model is more suitable for CDSNs. Moreover, the LTP parameters are optimized by the LTP-PODA algorithm to obtain an optimization plan. Configuring the optimization plan for LTP improves the protocol transmission performance by at least 18.77% compared with configuring the other parameter configuration plans.     

Experimental and numerical investigation on opposing plasma synthetic jet for drag reduction

Experimental and numerical studies are carried out to validate the potential of opposing Plasma Synthetic Jet (PSJ) for drag reduction for a hemisphere. Firstly, flow field changes of opposing PSJ are analyzed by comparing the experimental schlieren images and simulation results in a supersonic free stream of Mach number 3. As PSJ is a kind of unsteady pulsed jet, the shock standoff distance increases initially and then decreases under the control of PSJ, which corresponds to the change of the strength of PSJ. Accordingly, the amount of drag reduction of the hemisphere increases initially and then decreases. It is found that there is a short period of “drag rise” during the formation of PSJ before the drag reduction, which is induced by the generation of normal shock waves and the area difference of the cavity wall of PSJ Actuator (PSJA). Secondly, the effects of five parameters, including exit diameter, discharge energy of PSJA, Mach number, static pressure of incoming flow and angle of attack, on drag reduction of opposing PSJ were studied in detail by using numerical method. It is found that the Maximum Pressure Ratio (MPR) has a significant impact on the average drag reduction for a configuration-determined PSJA. For the configuration selected in this study, the flow field of opposing PSJ shows typical Short Penetration Mode (SPM) in a control cycle of PSJ when the MPR is less than 0.89. However, the flow field shows typical Long Penetration Mode (LPM) at some time when the MPR is bigger than 0.89. Relatively better drag reduction is achieved in this case.     

指数法在反舰导弹武器作战能力评估中的应用

指数法是一种定量评价事物属性的方法，文中分析了影响反舰导弹武器系统的能力层次结构，并在此基础上介绍了运用指数法评估反舰导弹武器作战能力的方法。