改进GPS多天线配置法姿态测量仿真研究

研究了采用双基线GPS多天线配置方案测量载体的姿态，通过改进的GPS多天线配置法完成对整周模糊度的解算，结合GPS载波相位信息测量得到基线矢量。该姿态测量方案能快速而准确地解算整周模糊度，解算方法算法简捷、计算速度快，并且不依赖GPS的码元信息，减小了跳周现象对测量结果的不利影响，使姿态测量精度得到提高，对于实时姿态测量(RAD)系统具有很好的应用价值。     

基于GPS-OEM板的低成本二维姿态测量系统

基于GPS-OEM板的低成本二维姿态测量系统,由数据采集与数据识别处理,模糊度与姿态解算,显示揪信息和编译动态链接库等模块组成.由两个GPS天线组成基线,接收GPS卫星信号,经连接电缆传到GPS-OEM板.再通过串行端口送至导航计算机,姿态解算软件对其经度、纬度等数据进行处理,解算完成后输出姿态测量结果.     

中长基线下机载GPS定位模糊度动态解算方法研究

在机载GPS定位中,当卫星信号中断、失锁时间较长时,不能利用周跳检测技术恢复模糊度,这时需重新计算模糊度。由于此时基准站和移动站处于中长基线状态,其距离和高程差均较大,对流层和电离层延迟残差较大,将影响模糊度固定。本文利用Kalman滤波和电离层加权模型,把电离层延迟残差当作未知参数和位置参数、模糊度同时求解,得到模糊度浮点解和协方差,并利用LAMBDA算法固定模糊度。算例结果表明：电离层加权模型能有效消除电离层延迟残差,能成功解算基线长度达69．5km的基线模糊度,且删除低仰角卫星有利于模糊度解算。     

双频载波姿态确定系统中的模糊度研究

为了满足卫星动态测姿系统的速度和精度要求,提出了一种单历元整周模糊度解算方法.该方法利用现代卫星系统多频观测条件,组成双频宽巷组合观测值,用约束条件确定宽巷组合初始整周模糊度备选值,采用多种检验方法剔除错误的模糊度组合,最后求解出用于姿态解算的单频载波相位整周模糊度值.经实验仿真证明,该方法简单快速,克服了传统TCAR技术模糊度确定错误率高的缺点,提高了正确率,适合单历元姿态确定.     

基于UKF弹体滚转姿态测量方法研究

利用磁阻传感器和GPS等器件的测量信息,建立了地磁/GPS组合弹体姿态测量解算模型,对弹体姿态信息进行实时测量解算。为了提高弹体飞行姿态测量解算精度,建立了弹道滤波方程,采用UKF算法进行数据滤波处理,结合磁阻传感器的输出信息对弹体滚转姿态进行实时解算。数值计算及仿真结果表明:相比于直接使用GPS输出的速度信息进行姿态解算,通过UKF滤波处理后,可以使得地磁/GPS组合测量解算的结果更准确,提高了弹体姿态解算精度。     

基于正则化的陆基伪卫星整周模糊度解算方法

针对特殊地理环境下陆基伪卫星系统整周模糊度解算精度不足的问题,提出了基于TIKHONOV正则化方法的陆基伪卫星定位系统整周模糊度在线解算的方法。该方法根据陆基伪卫星定位系统所处的环境,使用TIKHONOV正则化方法对观测方程的法方程进行处理,对法方程的病态性进行削弱。仿真验证结果表明,使用TIKHONOV正则化方法削弱法方程的病态性后,整周模糊度浮点解的解算误差缩小了数十倍,据此搜索出的整周模糊度整数解与真值相同。由此可得出结论,该方法能够提高陆基伪卫星定位系统整周模糊度的解算精度。     

机载双频GPS载波相位定位算法与算例

周跳检测、准确消除电离层和对流层残差影响、快速固定新星和失锁卫星的模糊度等,都是机载GPS载波相位差分定位中定位精度能否达到分米级的关键因素。文中利用电离层残差法和M-W组合探测周跳,使用电离层浮点模型和对流层经验模型改正电离层和对流层残差,并用扩展Kalman滤波求解GPS双差方程,采用LAMBDA算法求解模糊度。算例结果表明,该方法能有效探测动态数据周跳,消除电离层和对流层残差影响,恢复失锁卫星和新星模糊度,使得定位达到分米级,并利用飞机上2台GPS接收机的移动基线解算结果验证了该定位精度。     

人工神经网络改进的AHRS/GPS紧耦合滤波算法

以陆用AHRS/GPS紧耦合系统为研究对象,建立了基于伪距-伪距率-航向角的组合观测数学模型,采用RBF网络辅助的EKF导航滤波器,逼近组合系统的非线性特性,实现自适应的导航参数解算.仿真结果表明:方法可快速、准确地逼近系统非线性模型,估算的姿态角误差均方差较标准EKF减小了约5.9%～22.8%.在传感器精度有限的情况下,所获得的导航精度和动态性能均有提高.     

基于GPS双天线的弹体姿态测量方法

针对舰载武器弹体飞行姿态信息难以实时准确测定的问题,提出采用GPS双天线配置方案来测量飞行弹体姿态的方法,该方法首先建立用于飞行弹体姿态测定的观测模型,结合对GPS载波相位信息求解基线矢量及整周模糊数解算的分析推导,通过坐标系的变换得到弹体的姿态信息。数值计算表明,弹体的俯仰角误差范围在±0.8°之间;偏航角误差范围在±0.7°之间,计算结果验证了模型和算法的有效性。     

基于互补-粒子滤波的MEMS 传感组件姿态数据融合算法

为解决现有的MEMS传感组件精度低、误差大和磁传感器测量的航向角数据噪声大、精度低等问题,提出基于互补-粒子滤波的姿态融合解算方法.先用互补滤波算法结合加速计和磁力计对陀螺仪的姿态角进行修正,再采用四元素法对陀螺仪数据进行粒子滤波.仿真实验结果证明:该算法能快速解算出姿态角,提高解算精度.     

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.     

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.     

Experimental Research on Output Performances of Giant Magnetostrictive Actuator

The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.     

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.