半实物仿真系统精度分配方法初探

本文对寻的制导武器系统的半实物仿真系统精度分配做了初步性研究,提出了在这种仿真中半实物仿真的瞄视误差的分配方法。同时对影响瞄视误差之一的三轴飞行平台的指向误差做了研究,并提出了影响指向误差的三种因素的分配方法。在仿真系统的动态精度方面提出了设备动态频带的限制标准和速率稳定度的限度。     

随动系统动态误差对舰空导弹制导精度的影响分析

发射角精度对于导弹飞行中的初始扰动会产生比较大的影响,发射角精度主要受随动系统的影响。首先对随动系统的输入信号进行了分析,讨论了目标等速等高直线飞行的情况,得出了输入信号变化的复杂性,从而得出讨论动态误差的必要性;然后对数字伺服控制系统进行了讨论,通过对单位反馈系统传递函数的分析,得到在一阶系统下的动态误差系数;最后根据典型目标的特性,仿真了动态误差的变化规律,研究了随动系统的动态误差对舰空导弹拦截目标的脱靶量影响。     

基于四元数的大角度姿态机动反馈线化控制

采用一套基于旋转群代数的表示姿态误差的新方法,并采用非线性系统的反馈精确线化理论,用基于旋转群代数缩减四元数表征的姿态误差,以缩减四元数描述所得的系统姿态动力学方程为基础,将挠性振动部分做为零动态子系统处理,构造了能够实现精确的线性姿态误差动态特性的挠性飞行器大角度三维姿态机动非线性解耦控制律,并得到了仿真验证。     

加速度计动态误差系数标定的仿真研究

在分析和研究加速度计动态输出的基础上,综合了加速度计仿真模型和三轴转台数字模型以及测试误差的特性。利用MATLAB进行了仿真,使得在三轴转台上标定加速度计动态误差系数有了清晰的先验认识和结果预期。     

机载火控系统动态精度建模与稳定性研究

机载火控系统精度试验后获得的射击诸元误差序列通常为非平稳的随机过程,其稳定性与误差模型都是未知的,根据此数据序列的误差特性,对于机载火控系统动态精度试验所获得的数据,利用时间序列模型的有关理论,建立动态误差数据序列的AR模型,并且对获得的误差模型通过计算其特征方程的特征根分布来判断系统的稳定性.通过对某型机载光电火控系统的半物理仿真试验数据的分析建模,验证了本方法的有效性.     

阻尼对压阻式高g值加速度计动态特性的影响

针对动态校准过程中,压阻式高g值加速度计出现动态特性欠佳的情况,用实例与建模仿真相结合的方法,分析了阻尼对压阻式高g值加速度计动态特性的影响,得出若加速度计内部阻尼设计过小,则传感器动态特性差。仿真表明:合理调整阻尼比范围在0.1～0.25时,传感器动态特性较好,时域内响应信号上升时间快、幅值误差小、衰减速率快,频域内谐振分量少。实验表明:该影响确实存在,阻尼比满足要求的传感器具有较好的动态特性。     

模糊Terminal滑模变结构控制

普通的Terminal滑模控制器当误差较大时收敛的速度较慢,文中提出了一种新的Terminal模糊滑模控制方法.使其既具有普通Terminal滑模控制的优点,即保证了输出跟踪误差在有限时间内收敛到零,使系统的动态性能优于普通滑模中的性能;又使系统具有快速响应的特性,而且具有较好的鲁棒性.仿真结果表明,使用Terminal模糊滑模控制器控制十字梁实验系统是可行的.     

基于新息自适应滤波的惯性测量单元误差在线标定方法研究

考虑到空天飞行器飞行环境和运动特性下导航传感器误差的噪声统计特性不可能完全精确已知,若使用常规卡尔曼滤波进行在线标定,将会导致滤波精度下降甚至发散。设计一种基于新息自适应滤波方法的惯性测量单元(IMU)误差在线标定方案和算法,克服常规卡尔曼滤波需预先知道噪声统计特性的不足,设计包含IMU安装误差、刻度因子误差和随机常值误差在内的27维高阶状态变量的误差标定模型,分析提出可同时对系统噪声和量测噪声协方差矩阵进行动态调整的新息自适应滤波在线标定算法。仿真验证实验表明,相较于采用常规卡尔曼滤波以及Salychev O自适应滤波算法进行在线标定,所设计的新息自适应滤波在线标定方法能更有效实现对IMU误差的动态标定及补偿,进一步提高了惯性导航系统精度。实物验证实验表明,该方法可有效标定IMU误差残差,提高导航精度,为工程应用带来较大便利。     

某牵引高炮液压调平油缸动态特性研究

建立了某牵引高炮液压调平油缸的数学模型和仿真模型,用Matlab数字仿真软件包对调平油缸进行动态特性仿真;分析了影响系统的动态特性的主要因素。仿真结果表明,Simulink模块是对液压系统的动态特性进行仿真的一条有效途经。可以推广到其它产品,进一步实现液压系统设计标准化和最优化,提高对武器系统的总体设计能力。     

基于多体动力学的弹—伞系统动态特性仿真

着重对一种弹-伞系统的动态特性进行了仿真计算。计算时，以刚体弹道代替传统的质点弹道，利用多体动力学方法作理论分析，在Solid Works和MSC．Aadms中建立系统的动力学模型，进而进行了弹-伞系统的动态特性仿真，主要是过载仿真计算。与理论计算比较，结果相近，证明了仿真计算的可靠性。     

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.