火星环绕器次表层探测雷达发展综述

火星环绕器次表层探测雷达能够实现环火轨道火星次表层结构高分辨探测,为深入研究火星地质结构提供科学数据。针对目标介质分层的探测问题,进行了火星环绕器次表层探测雷达发展综述。详细介绍了火星环绕器次表层探测雷达的发展现状、探测原理、指标计算方法及关键技术,并对火星环绕器次表层探测雷达的发展趋势进行了展望。     

世界典型火星探测发射轨道及窗口拓展分析（英文）

由于运载火箭自身特点及飞行航、落区约束的差异,致使世界典型运载火箭直接火星探测任务的发射轨道存在明显不同。从直接火星转移的飞行力学原理的角度进行了分析,重点关注了典型火星探测任务的轨道剖面设计及窗口拓展方法,完成了对当前火星探测任务典型出发轨道特点的分析总结。     

一种适应大偏差工况的改进摄动制导方法

摄动制导方法简单、可靠,但其对大初始轨道偏差、大推力偏差或故障工况适应性差,近年来逐渐被迭代制导技术所取代。但迭代制导姿态振荡大、不适用于气动作用强烈飞行段。提出一种基于速度主量在线插值的改进摄动制导方法,从稳定性角度提出导引回路增益及网络参数设计方法。结果表明,本方法显著提升大初始速度偏差、大推力偏差工况下的轨道精度,姿态明显比迭代制导方案平稳。     

使用遗传算法和B平面参数进行月球探测器地月转移轨道设计

通过遗传算法和B平面参数对月球探测器地月转移轨道进行了设计和计算，计算结果表明，结合遗传算法和B平面参数可以很好地解决探月轨道搜索的全局性和快速收敛性问题。     

火星飞机的多胞LPV鲁棒控制器设计

随着火星探测的日益发展,火星飞机作为一种中尺度探测手段,能够很好地补充轨道和地表探测器之间的能力空白。针对火星飞机的强非线性、参数不确定性的特点,提出了一种火星飞机的多胞LPV变增益H∞控制器设计方法。首先依据火星飞机的纵向非线性模型,在进行研究的飞行包线内选取适量平衡工作点进行雅可比线性化,通过线性化后的线性时不变系统数值拟合得到系统的LPV模型;然后通过张量的高阶奇异值分解理论进行张量积建模,实现火星飞机LPV模型的多胞形表示。最后设计基于LMI求解的鲁棒变增益控制器,使对象能够克服不利特性的影响,能够完成指令信号的快速跟踪并且使系统具有较强的鲁棒性。     

亚轨道飞行器返回轨迹设计方法

针对亚轨道飞行器返回轨迹设计难点以及当前已有方法和模型的不足,提出了一种亚轨道飞行器返回轨迹设计方法。将返回轨迹分为初始返回段和机动转弯段,在机动转弯过程引入航向角偏差参数,并根据该参数标志的转弯终点对倾侧角进行迭代求解,能够有效处理亚轨道飞行器返回过程大范围机动转弯问题以及返回过程的各类约束,并通过算例验证了方法的可行性。设计方法符合亚轨道飞行器返回轨迹特点,能够满足设计要求。     

预定目标的在轨服务飞行器待机轨道分析

为确定单艘在轨服务飞行器(on-orbit Service Vehicle,OSV)针对预定目标的待机轨道,综合轨道动力学和球面几何学原理,利用经典二体动力学模型、霍曼转移轨道模型以及球面三角几何关系,设置具体实例分析OSV针对低、中、高轨道目标的待机轨道选择方法,得到轨道平面调整的能耗和变轨位置与目标轨道平面参数的变化关系,提出待机轨道参数优化的一般思路。该研究可为OSV实施"一对一"在轨服务的待机轨道选择提供理论依据。     

火星探测器轨道设计与优化技术

介绍火星探测器轨道设计以及优化技术,并对大推力轨道设计方法、小推力轨道设计方法以及借力飞行轨道设计方法等进行综合分析,为未来的火星探测器轨道设计提供参考.     

基于最速下降的火星探测机会确定方法

@@@@采用变分法推导得出指标函数的数值偏导数矩阵,进而构造出一种最速下降法,能快速确定燃料最优两脉冲火星交会机会。算例表明,该方法能从 Pork-Chop 的概略搜索结果出发,快速给出2015~2018年度的探测火星机会,其地球出发能量仅7.7498 km2/s2,火星抵达速度为2.9747 km/s,地火转移时间约208.6天。此外,最速下降法还可以作为一种通用的深空探测机会搜索与转移轨道设计方法,在金星、木星、土星等星际任务分析中发挥作用。     

预定命中态势下鱼雷二次转角射击的一种解法

针对预定命中态势下鱼雷二次转角射击参数求解问题,以鱼雷一次转角后的直航时间为条件,通过调整鱼雷开始二次转角前相对目标的“一次相遇点”位置,建立了预定命中态势下的鱼雷二次转角射击鱼雷与目标瞄准点相遇模型,给出了模型参数求解的迭代方法并进行了仿真验证,结果证明了所建立模型的正确性,满足了鱼雷二次转角设计参数求解要求。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

A Study on the Estimation of Aeroheating upon the Warhead Nose at Supersonic Speed

An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD （computational fluid dynamics） and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.