层次建模技术在火炮虚拟现实系统中的应用

建立了一种层次结构的数据模型并将其应用于火炮虚拟现实系统中。为了继承已有的三维实体模型,减少复杂建模的工作量,根据三维实体模型和虚拟现实模型的特点,建立了双层次结构的火炮模型。整个火炮模型分两层,实体层模型用于火炮的结构设计与优化,多边形网格层模型用于满足视景仿真与虚拟场景中的交互性。在此基础上,完成了某自行火炮的发射动力学仿真,并使仿真结果在虚拟场景中得到体现。结果表明,整个数据模型不仅可以精确地表示火炮实体,还能够满足虚拟场景的实时可视化要求。     

高炮刚柔耦合动力学仿真及二次开发研究

介绍了高射炮弹炮刚柔耦合发射动力学仿真及基于ADAMS的二次开发技术.在全炮系统的动力学模型中,对身管进行了柔性化处理,并考虑了弹丸与柔性身管的相互作用,计算了火炮连续发射时的动力学响应,为全面分析影响射击精度的原因提供了一定的参考价值.同时,基于ADAMS定制了适用于交互式发射动力学仿真的菜单和对话框,为火炮产品的虚拟设计提供了技术基础和工具.     

自行火炮发射过程的可视化仿真

基于多体动力学理论建立了某自行火炮的动力学模型，以第1类Lagrange方程推导了动力学方程。采用动力学分析软件ADAMs并结合I—DEAs软件进行了动力学模型的可视化仿真，避免了传统火炮设计理论引起的系统建模的误差。两种工况下的仿真结果表明：该动力学模型能够反映火炮发射过程的动力学规律，利用ADAMS进行火炮发射动力学分析是可行的。     

基于射击稳定性的车炮匹配参数分析

车炮匹配性是装甲车辆总体性能的重要组成部分之一.以某坦克炮的虚拟样机发射过程系统的射击稳定性仿真为基础进行了车炮匹配参数分析.为正确预测火炮系统主要部件的运动和受力规律,研究车炮匹配性评价在火炮系统射击过程的参数影响,建立了火炮系统的多刚体动力学模型.仿真计算结果表明火炮射击时,火炮和车体组成的系统做幅度较小的周期运动或衰减运动,系统具有可靠的运动稳定性和安全性.     

某火炮自动机虚拟样机建模与仿真

为了获得火炮发射时自动机的动力学响应,对火炮自动机虚拟样机的建模和仿真进行了初步探讨和研究。在对某火炮自动机的结构组成和机构动作分析的基础上,应用ADAMS软件建立虚拟样机模型,利用点-线约束、实体-实体接触副模拟自动机主要构件间的接触和碰撞,基于有限元方法,建立有限元模型,手工划分网格保证质量,施加边界条件,近似计算接触和碰撞刚度,采用脚本仿真的方法对自动机机构动作进行了多体系统动力学分析,获得了令人满意的仿真结果。     

基于虚拟样机的自行火炮发射动态性能研究

利用ADAMS/ATV和Pro/E建立某型自行火炮射击时的多体系统动力学模型,采用第一类拉格朗日方程建立系统的动力学方程.该模型由249个刚体组成,共有1275个运动自由度.将发射时的外载荷施加于相应位置进行仿真,计算得到火炮后座复进的运动规律,结果表明虚拟样机模型后座复进位移和速度的变化符合火炮实际后坐复进规律.     

轻型车载火炮二维后坐动力学研究

针对车载火炮轻量化技术中的后坐阻力控制问题,开展了二维后坐系统动力学研究.通过后坐运动分析,建立了二维系统运动微分方程,结合车载火炮射击工况,进行了受力分析,进而建立了轻型车载二维后坐火炮的发射动力学模型,并进行了仿真计算.分析结果表明,采用二维后坐系统能够有效减轻火炮后坐阻力.     

基于多体动力学的火炮虚拟现实系统实时仿真

对虚拟现实技术及其在火炮虚拟样机中的应用进行了研究.基于MultiGen Creator和Vega软件平台,开发出火炮虚拟现实仿真系统,论证了整个系统的软硬件配置,介绍了基于MultiGen Creator的建模方法以及整个虚拟环境的生成.设计了某自行火炮的动力学仿真发生器并将其应用于虚拟现实系统中.仿真结果表明,该系统能够逼真地演示出火炮行进、操瞄以及发射过程,满足了系统仿真的实时要求,可以对现代火炮设计起优化、参考作用.     

火炮发射药床冲击破碎动力学仿真研究

为了研究发射装药引起膛炸的基本原理,确保火炮武器系统发射过程安全,实现末端毁伤效应,从理论分析计算的角度出发,基于离散单元法,建立了火炮发射药床冲击破碎动力学仿真模型,模拟了大口径火炮发射药床在燃气流冲击载荷下的破碎过程,并与有限元计算软件LS-DYNA的结果进行对比,结果表明,离散单元法和有限元法计算结果几乎一致,验证了该方法的准确性。该计算方法对发射装药发射安全性研究具有一定理论实用价值。     

基于虚拟样机的某型速射迫击炮自动机运动学仿真研究

为获得某速射迫击炮发射时自动机的动力学响应,对该武器自动机虚拟样机的建模和仿真进行初步探讨和研究。在对某火炮自动机的结构组成和机构动作分析的基础上,应用ADAMS软件建立虚拟样机模型,并结合实验数据和理论数据对自动机连发射击仿真结果进行对比,再以虚拟样机为工具,对自动机的动力学特征进行仿真分析。结果表明,该样机是可行、正确的,可为修改该武器结构运动特性以及提高作战效能奠定基础。     

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。     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

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.     

Design and Implementation of One Missile Visual Simulation System Based on OpenGL

The implementation of a missile＇s visual simulation system is explained that is developed with OpenGL（open graphic library） and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile＇s data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.     

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.     

Dynamic Encryption Technology in Ad-hoc Networks

A new dynamic encryption application in ad-hoc networks is proposed. The advantages of this method are its being able to use the previous ciphertext as a seed of a new encryption process, rendering the encryption process effective in all communication process by continuous dynamic key generation together with synchronization, and its capability to cut back on system bandages to a greater extent, which is valuable for the ad-hoc circumstance. In addition, the rationality and effectiveness of this novel encryption method have been verified by the test results.     

An Experimental Study on Electro Chemical Machining of Microelectrode

Puts forward a new method in machining microelectrode by electro chemical machining （ECM） and plastic deformed theory. The procedure of this method is to machine the microelectrode according to the basic rule of ECM theory at first. Then, with the change of ECM machining parameters, one of the microelectrode ends is exerted by a load. As a result, the elastic and plastic deformation is produced at the machining section and the microelectrode diameter is reduced. It has been proved that the proposed method can determine the optimum machining parameters to machine the microelectrode of Cu.     

Unscented Kalman Filter for Autonomous Warship Attitude Determination

To address a problem of autonomous attitude determination algorithm using gravitational field and geomagnetic field observation, a new recursive optimization autonomous attitude estimation algorithm is proposed. The algorithm is based on unscented Kalman fiher(UKF), and can synchronously provide the attitude rate information. The simulated results show that the measurement precision of the method could be increased by 2 times compared to that of the common methods.     

Error Coefficient Estimation of Inertial Platformin Its Calibration

The error coefficient estimation of inertial platform in the course of its consecutive ground calibration is studiedA separate-bias algorithm is adopted to estimate the error parameters effectively. The ill-conditioning problem of the equation solution caused by the huge state dimension is also resolved. And the simulation result shows its validity.