阵风干扰下平台漂移误差系数辨识研究

飞行器竖立在发射阵地时,会受到阵风的干扰产生振动,从而影响惯性平台的标定精度。为了更好发辨识阵风干扰下的平台漂移误差系数,根据弹体结构力学原理选用了达文波特（Davenport）阵风模型计算出了飞行器在一定风速下的最大振幅,并将振动理想化为欠阻尼振动进行建模。将这个振动加入平台漂移误差建模的过程中。通过建立起平台欧拉角变化率与漂移角速率建立描述平台漂移的状态空间方程,将误差系数看作状态变量,利用扩展卡尔曼滤波算法进行辨识。辨识效果图显示参数收敛速度快且趋于稳定,在加入随机噪声的情况下计算3组数据,得出稳定、可信的结果。     

较大幅度摇摆条件下舰船捷联惯导自对准研究

研究摇摆基座上捷联惯性导航系统的初始对准技术.提出了对加速度计输出进行分析并对其进行积分的方法,来抑制干扰的影响.通过最小二乘法估计初始失准角与陀螺常值漂移,从而运用姿态误差角方程推算出相应时刻的失准角.仿真结果表明该方法切实有效.     

某型导弹平台漂移系数分离测试方案分析

针对某型弹道导弹半姿态平台提出了一种分离陀螺漂移系数的测试方案——九位置翻转分离测试。给出了陀螺漂移误差模型,根据误差模型对平台上3个陀螺处于不同位置时输出轴干扰力矩进行了详细的分析,并建立了力矩平衡方程组。通过列解力矩平衡方程组分离出漂移误差模型中的各项漂移误差系数。该测试方案已成功地应用于某型弹道导弹的平台单元测试。     

激光捷联惯导系统线振动基座下误差参数辨识仿真

本文对振动基座和静态基座下激光陀螺捷联惯导系统对准过程进行了仿真。主要对比了两种情况下激光陀螺漂移误差和加速度计偏置误差的收敛速度和收敛精度。结果表明,同静态二位置情况相比,振动环境下,系统可观测程度有明显改善,加速度计偏置收敛速度提高近一倍,陀螺漂移收敛速度也有提高,并且振动环境下的仿真更接近惯导系统工作状态,具有较强的实用价值。     

潜射导弹捷联惯性平台快速调平补偿方案研究

潜射导弹在动基座上发射,由于动基座的非匀速运动,给弹上制导平台的调平带来了误差.通过对加速度的干扰进行定量分析,推出了动基座运动加速度干扰产生的调平等效误差角,给出了一种快速调平补偿方案.     

星敏感器辅助的捷联光纤航姿误差在线估计方法研究

提出了一种基于星敏感器辅助的舰载光纤捷联航姿系统（SAHRS）误差在线估计方法,以初始时刻舰船惯性坐标系为参考系,直接以星敏感器输出惯性姿态为基准,估计陀螺仪的常值漂移;在舰船系泊状态下,以重力矢量在惯性空间的投影为基准,利用比力的积分量构建观测值,估计加速度计零偏。该方法无需拆卸系统,陀螺与加速度计误差估计完全分离,估计收敛速度快、实时性好。仿真结果表明：该方法可实现在静止基座和摇摆基座条件下捷联航姿陀螺仪常值漂移及水平加速度计零偏的在线估计,估计精度分别优于0.02°/h和50 μg.     

单轴旋转阻尼惯导仿真研究

为降低单轴旋转惯导输出的振荡误差,提高系统精度,在单轴旋转惯导中引入了阻尼网络。采用时间步距仿真技术,建立了基于Simulink的动基座单轴旋转阻尼惯导仿真模型,并分别对无阻尼和水平阻尼情况下,常值漂移和随机漂移对单轴旋转惯导系统的影响进行了仿真分析。结果表明,在单轴旋转惯导中引入阻尼网络能够消除系统舒拉周期振荡误差和傅科周期振荡误差,抑制随机漂移的影响,大大提高了单轴旋转惯导系统的输出精度。     

捷联式陀螺寻北仪误差分析与试验研究

对产生捷联式挠性陀蚴寻北仪误差的主要因素进行了分析。试验结果表明：水平姿态角较 ,与重力加速度的一次项有关的陀螺漂移是产生建立经误差的主要原因之一。应用椭圆低通滤波器对陀螺仪输出信号进行处理,能较好地减小基座扰动对寻北精度的影响。     

地磁信号检测系统误差分析与补偿方法研究

高精度、高分辨率地磁信号检测是地磁匹配导航的基础,在分析地磁信号检测系统误差来源的基础上,建立了三轴磁传感器自身误差以及软硬磁干扰误差综合模型,介绍了一种基于空间点地磁矢量不变的椭球拟合校准算法.通过实验比较,结果表明:该方法能有效抑制与补偿地磁信号检测误差,包括三轴磁传感器零点漂移引起的误差、标度因数不一致引起的误差...     

基于BP 神经网络的风洞传感器非线性误差修正方法

针对风洞试验时传感器测值受到非线性误差干扰的问题,提出基于BP神经网络的风洞传感器非线性误差修正方法.利用BP神经网络强大的非线性映射能力,通过神经网络模型融合传感器校准数据对传感器的测量误差进行计算,并根据网络计算误差对传感器测值进行修正.试验结果表明:该方法能有效地减小非线性误差对传感器测值的影响,提高传感器的测量精度.     

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.