低密度双基体烧蚀防热材料

采用硅基针刺毡作为增强体、先后浸渍无机和有机树脂基体的两次复合工艺,可制成密度＜1.20g/cm3的双基体烧蚀防热材料.通过马弗炉烘烤、石英灯静态隔热、电弧风洞加热三种方式考核材料的剩余强度、抗变形能力、隔热性能和抗冲刷能力.结果表明:该材料在有氧条件下,经马弗炉1 100℃、3000s烘烤,剩余基体还有20wt％,材料仍具有一定强度;石英灯加热至l 200℃,总时长1200s的条件下,25 mm厚的试样最终背温＜120℃;电弧风洞考核显示,材料抗冲刷能力强,880 s时,25 mm厚材料背温仅有71℃.     

一种机载配电系统1553B总线设计

以1553B通信数据总线为研究对象,基于数字式控制器（DCU）平台,对一种机载配电系统1553B通信数据总线进行了设计研究。在具体硬件、软件的设计过程中,结合现代数字式控制器DCU的平台,以DSP的F240为核心,以DDC公司的BU-61580协议芯片为基础,实现了机载配电系统1553B的机上通信要求,并通过地面电网联试试验验证了该设计的有效性。     

基于二项分布的优化序贯截尾检验方法分析计算

基于二项分布的优化截尾序贯检验法能降低平均试验数,可有效用于导弹试验检验方案中,但该方法存在实际风险计算不准确的特点。文章在深入分析该算法基础上,提出采用马尔科夫链的方法计算试验风险,给出了试验方案制定步骤,并用实例计算说明该方法的正确性及可行性。     

公务机机翼气动外形优化研究

随着世界经济贸易的发展,轻中型公务机愈发受到客户的青睐。为了进一步提升高速涡扇公务机的总体气动性能,本文采用基于全速势方程（TRANAIR）的流场快速求解方法,集成序列二次规划（SQP）优化算法和类函数/型函数变换（CST）自由变形（FFD）技术,对某轻中型高速涡扇公务机机翼进行多点优化设计研究,并对优化结果进行对比分...     

High-temperature tribological behaviors of a Cr-Si co-alloyed layer on TA15 alloy

A Cr-Si co-alloyed layer was successfully deposited on TA15 alloy by the double glow plasma surface technology to improve its poor wear resistance at elevated temperature.The microstructure,composition,and phase structure of the layer were investigated by SEM,EDS,and XRD.The tribological behaviors of the Cr-Si co-alloyed layer at 20 ℃ and 500 ℃ were analyzed in details.The results indicated that the friction coefficient and wear rate of the Cr-Si coalloyed layer at 20 ℃ and 500 ℃ were much lower than those of the substrate,which was due to higher hardness and superior elastic modulus.This layer may become an approach to effectively improving the wear resistance of TA15 alloy at elevated temperature.     

空战机动决策集模型分析

空战机动决策集模型是自主空战机动决策技术的基础,直接影响着空战机动决策的效果。本文综述了应用最为广泛的两类典型空战机动决策集模型,分析了现有基本机动动作决策集模型和典型战术动作决策集模型的特点和不足,提出了机动决策模型的改进方法。     

Model-based robust estimation and fault detection for MEMS-INS/GPS integrated navigation systems

In micro-electro-mechanical system based inertial navigation system（MEMS-INS）/global position system（GPS） integrated navigation systems, there exist unknown disturbances and abnormal measurements. In order to obtain high estimation accuracy and enhance detection sensitivity to faults in measurements, this paper deals with the problem of model-based robust estimation（RE） and fault detection（FD）. A filter gain matrix and a post-filter are designed to obtain a RE and FD algorithm with current measurements, which is different from most of the existing priori filters using measurements in one-step delay. With the designed filter gain matrix, the H-infinity norm of the transfer function from noise inputs to estimation error outputs is limited within a certain range; with the designed post-filter, the residual signal is robust to disturbances but sensitive to faults. Therefore, the algorithm can guarantee small estimation errors in the presence of disturbances and have high sensitivity to faults. The proposed method is evaluated in an integrated navigation system, and the simulation results show that it is more effective in position estimation and fault signal detection than priori RE and FD algorithms.     

一种自适应各向异性的SAR图像去噪算法

为了在抑制噪声时尽可能保留图像边缘信息,提出一种自适应各向异性SAR图像去噪算法。该方法设计一组具有不同尺度和方向的滤波器模板,针对不同图像边缘的局部特征计算出滤波器的尺度和方向,选择最优匹配的各向异性滤波器,从而可以在抑制噪声的同时很好地保留边缘。仿真实验表明,提出的自适应各向异性SAR图像去噪算法具有很强的噪声抑制和边缘保持能力,并且具有较高的实效性。     

单相流体回路控温算法建模与仿真分析

针对我国新的载人航天器在控制密封舱空气温湿度同时,要精确控制流体回路上电池等大热耗设备温度的需求,文章给出了航天器单相流体回路的PID控制、模糊增量控制和专家控制算法,解决了控温点前存在大热容和大热耗设备的流体回路控温问题。新的单相流体回路控温算法的提出和应用,可以有效简化流体回路复杂程度,减少10%的热控质量和功耗。     

晶振式非接触表面轮廓传感器的动态特性

从理论上对线性伸展模式的石英振子的动态特性进行了分析，讨论了在近场效应作用下，影响晶振品质因数的各种阻尼，并将所获得的解析模型与实验结果进行了比较。