基于逆向导航算法的捷联式惯性导航系统改进优化对准方法

快速性和精度是捷联式惯性导航系统动基座初始对准的重要指标。优化对准方法（OAM）在短时间内难以获取足够多的观测信息,导致对准性能降低。针对此问题,提出一种基于逆向导航算法的改进动基座初始粗对准（IMCA）方法。通过逆向导航算法对存储的陀螺仪和加速度计数据进行虚拟延长并加以反复利用,扩展积分区间长度,以构建新的观测矢量、实现对准精度的提升。推导了载体坐标系下的OAM,分析了观测矢量包含的信息量对姿态确定精度的影响。基于车载实测数据,分别利用OAM和IMCA方法进行动基座初始对准试验,结果表明：相比于OAM,IMCA方法可在相同条件下实现更高精度的初始对准;IMCA方法应用在载体坐标系下动基座初始对准中是可行、有效的。     

捷联惯导系统动基座初始对准研究

建立了捷联惯导系统动基座对准的误差模型,利用分段定常系统可观测性分析理论和方法对系统动基座初始对准时的可观测性进行了全面分析.并采用卡尔曼滤波技术,对系统在各种运动基座初始对准情况下的平台误差角进行了估计,给出了方差仿真曲线,比较了静基座与在这些运动情况下的卡尔曼滤波器的估计效果.仿真结果表明,在捷联惯导系统动基座初始对准过程中,可以通过载体线运动和角运动的改变来提高系统的可观测性和状态变量的可观测度,从而提高估计的精度和速度.     

惯性导航系统动基座对准对舰舰导弹捕捉概率的影响

采用惯性导航系统的舰舰导弹作为海战场最重要的攻击武器,能否快速准确地在舰艇上对导弹捷联惯性导航系统进行初始对准,是影响舰舰导弹捕捉概率的重要因素。动基座对准误差导弹捷联惯性导航系统作为的初始误差,会随着工作时间增长不断累加,导致末制导雷达开机时导弹散布误差和航向误差角不断增大,将致使末制导雷达的捕捉概率下降。基于动基座初始对准误差对导弹飞行控制误差的影响,以目标位置误差圆分布为基础,建立舰舰导弹捕捉概率计算模型,通过不同条件的参数设置,仿真计算出某型舰舰导弹动基座初始对准误差对目标捕捉概率的影响。结果表明捕捉概率近似线性下降,下降值约为静基座对准时的4.2%~6.5%.     

快速高精度的二次对准技术研究

提出了二次对准技术,即在首次对准的基础上进行再对准．成功地解决了动基座对准。利用零速修正的方法进行初始对准,在双轴手遥转台上完成了动基座对准试验。试验结果表明．二次对准这一动基座对准技术是可行的。二次对准技术可以显著提高对准精度并缩短对准时间．尤其适用于动基座对准。     

捷联惯导系统动基座对准中的可观测性分析

建立了捷联惯导系统动基座对准的误差模型,利用分段定常系统可观测性分析理论和方法对系统动基座初始对准时的可观测性进行了全面分析.定性地得出了载体不同运动对系统可观测性的影响.采用卡尔曼滤波方法,对平台误差角进行了估计,给出了仿真曲线,验证了分析结论.     

捷联惯导系统动基座对准中的可观测性分析与研究

建立了捷联惯导系统动基座对准的误差模型,利用分段定常系统可观测性分析理论和方法对系统动基座初始对准时的可观测性进行了全面分析,定性地得出了载体不同运动对系统可观测性的影响结果.分析结果表明,在动基座对准过程中,无论载体是线运动还是角运动,在一定条件下都能够提高系统的可观测性,进而提高卡尔曼滤波器的估计速度和精度.并采用卡尔曼滤波方法,对平台误差角进行了估计,给出了仿真曲线,验证了分析结论.这为研究捷联惯导系统的快速精确对准方法奠定了理论基础.     

捷联惯导系统动基座对准中的可观测性分析与研究

建立了捷联惯导系统动基座对准的误差模型，利用分段定常系统可观测性分析理论和方法对系统动基座初始对准时的可观测性进行了全面分析，定性地得出了载体不同运动对系统可观测性的影响结果。分析结果表明，在动基座对准过程中，无论载体是线运动还是角运动，在一定条件下都能够提高系统的可观测性，进而提高卡尔曼滤波器的估计速度和精度。并采用卡尔曼滤波方法，对平台误差角进行了估计，给出了仿真曲线，验证了分析结论。这为研究捷联惯导系统的快速精确对准方法奠定了理论基础。     

舰载导弹武器系统对基准信息的应用需求与展望

在海军武器装备中,惯导系统的应用越来越广泛。武器系统应用惯导系统将不能回避在动基座条件下进行初始对准这一难题,而动基座对准必须利用外界的基准信息。本文对基准信息的现状和在导弹武器系统中的使用情况进行了介绍和分析,对未来武器系统中的惯导系统完成初始对准时对基准信息的需求和使用方式进行了预测和展望。     

捷联惯导系统动基座初始对准中的可观测性分析

用分段定常系统可观测性分析理论和方法对系统动基座初始对准时的可观测性进行分析.定性地得出了载体的各种机动特性对捷联系统对准过程可观测性的影响结果.采用卡尔曼滤波法, 对平台误差角进行了估计, 给出了仿真曲线.结果表明, 动基座对准过程中, 载体的线运动和角运动在一定条件下能提高系统的可观测性, 从而提高卡尔曼滤波器的估计速度和精度.这为研究捷联惯导系统的快速精确对准方法奠定了理论基础.     

一种新的捷联惯导系统对准方法

针对舰载鱼雷捷联惯导系统的初始对准问题,提出了一种新的动基座快速传递对准方案——贯序传递对准方案。该方案采用＂先角速度匹配,后速度＋姿态匹配＂的方法,在基座角运动不明显时,使失准角快速收敛。运用卡尔曼滤波算法,对这一传递对准方法与速度＋姿态传递对准方案进行了仿真比较,研究结果表明,贯序传递对准方案具有更快的估计收敛速度,适用性更强。     

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.