航速惯导组合导航系统在AUV上的应用

捷联惯导多普勒（SINS/DVL）组合导航技术是自主水下航行体（AUV）导航系统中经常采用的算法。针对由于复杂海洋环境导致的DVL失效,使整个导航精度急剧下降的情况,该文将螺旋桨转速变换成AUV航速,利用航速惯导组合系统信息融合方法,提出了一种通过航速惯导组合导航的卡尔曼滤波算法,可以减小导航误差。仿真结果表明,该算法提高了系统稳定性,在短时间内可以满足AUV导航系统的定位需求。     

AUV组合导航系统中H∞滤波技术

为了提高自主水下航行器(AUV)组合导航系统精度,选择了捷联式惯性导航系统(SINS)、多普勒速度声纳(DVS)以及地形匹配导航系统(TAN)作为AUV组合导航系统导航传感器,建立了AUV组合导航系统的状态模型和导航传感器观测模型,运用了一种基于径向基函数(RBF)神经网络进行H∞滤波信息分配的信息融合方法,并进行了计算机软件仿真.仿真结果表明,在有色噪声情况下,AUV组合导航系统的导航姿态、速度和位置精度得到了提高,有效地克服了传统滤波容易发散的缺点,提高了AUV组合导航系统的容错性能和导航精度.     

水下航行器INS/GPS/DVL组合导航方法

针对自主水下航行器（AUV）受水下环境的局限难以提高导航性能的问题,提出了一种融合多传感器信息的INS/GPS/DVL组合导航方案,利用分散化滤波中的联邦Kalman滤波来实现AUV组合导航方案,通过动态信息分配系数优化了各子系统的导航信息,增强了AUV的导航性能。仿真结果表明,该方案充分提取了导航传感器的信息,有效地提高了AUV的导航精度和水下定位能力。     

UAV 组合导航半物理仿真系统设计与研究

为了验证GNSS／MLS／VNS／INS／RA构成的UAV五组合导航系统的航电综合、导航解算算法以及飞行控制律性能,设计了集机载导航传感器实物、物理效应器、飞行仿真系统、无人机地面站模拟系统、试验总控评估系统、视景与展示系统等的UAV导航与控制半物理仿真试验系统平台。平台能够考核组合导航系统的性能和功能。     

远程AUV组合导航技术研究

AUV通常采用SINS/DVL组合导航系统导航,然而在大航程时存在很大的定位误差.针对远程AUV的大航程及在水下状态自主航行存在的问题,提出定时引入GPS信息达到提高导航精度目的.文中重点介绍一种采用SINS/DVL/GPS水下组合导航方式,通过定时引入GPS信息,提出组合滤波器设计方案,仿真结果验证了此设计方案可有效提高系统导航定位精度.     

一种基于改进无迹卡尔曼滤波的自主水下航行器组合导航方法研究

针对自主水下航行器(AUV)导航系统对稳定性、精确性和实时性的需求,提出了一种基于改进无迹卡尔曼滤波(UKF)算法的捷联惯性导航系统/多普勒测速仪(SINS/DVL)组合导航新方法.通过分析中低精度组合导航系统的特点和误差模型,在系统的噪声模型为复杂加性噪声时,利用球面分布单形采样变换设计了一种简化UKF组合导航算法....     

一种利用单信标修正AUV定位误差的方法

针对配置有捷联惯导（SINS）／多普勒速度仪（DVL）／深度传感器组合导航定位系统的自主水下航行器（AUV）的定位误差随时间增大,以及采用GPS修正定位误差引起的AUV隐蔽性降低等问题,提出了一种利用水下固定单信标修正SINS／DVL／深度传感器组合定位误差的方法。该方法首先利用水声测距原理测量出AUV与水下固定单信标的距离,然后基于空间几何关系计算出AUV的实时位置,最后通过卡尔曼滤波连续修正AUV的定位误差。仿真结果表明,该方法可以有效减小AUV的定位误差,有较好的工程应用价值。     

基于降阶模型的GPS/PINS组合导航半实物仿真研究

文中基于卡尔曼滤波器降阶模型．设计了GPS／PINS实时组合导航跑车试验系统。跑车试验过程中实时采集GPS的位置和速度信息以及平台惯组的加速度和姿态角等信息．进行滤波解算，实时输出解算结果。试验结果表明．基于降阶模型的组合导航系统可以满意的完成导航任务。     

大航程AUV SINS/DVL组合导航定位精度研究

为了进一步提高AUV的导航定位精度,研究SINS／DVL组合导航系统在大航程AUV上的应用。首先,建立其误差分析模型;然后,提出使用常规kalman滤波方程计算误差的思想;最后,在系统噪声与观测噪声已知的情况下,应用常规kalman滤波算法进行仿真分析。结果表明,该滤波存在明显发散,导致误差方差阵失去非负定性,影响滤波增值。     

基于GPS卫星模拟器的AUV辅助导航半实物仿真系统开发

全球卫星定位系统(GPS)应用于远程自主水下航行器导航系统中,可利用其精密导航和定位能力对航位推算导航系统如惯导和多普勒导航的累积误差进行精密校正.本文设计一种采用GPS卫星定位导航模拟器、GPS接收机和仿真计算机构成的卫星导航仿真系统,旨在用于自主水下航行器AUV辅助导航系统的试验验证.文中对该系统的硬件接口设计和软件开发进行了论述,并进行了部分系统测试评估.测试结果表明,该卫星导航仿真平台工作可靠,最终的设计方案可用于AUV导航与控制半实物仿真系统中.     

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.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

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.     

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.