Dynamic Study on Rigid and Flexible Coupling System for Terminally Sensitive Submunition

A kinetic model of the rigid and flexible coupling system for terminally sensitive submunition is set up with Kane＇s method. The parachute is considered as a flexible body, the flexible displacement is expressed with modal spread method, the position of the parachute is expressed with a hybrid coordinate method, and the kinematics of the terminally sensitive submunition is analyzed. Ten generalized coordinates relative to the attitude of the terminally sensitive submunition are chosen, and the correlative generalized active forces, the generalized inertial forces, the generalized internal forces are calculated in turn. On the base of the Kane＇s method, the ten degrees of freedom dynamic equations for the coupled terminally sensitive submunition are finally set up. This model can be used to expediently simulate and analyze accurately the exterior ballistic trajectory of terminally sensitive submunition, and provide the overall design of the terminally sensitive submunition with some helpful references.     

Study on Effects of Diesel Engine Cooling System Parameters on Water Temperature

A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multiple system parameters on the water temperature are analyzed. The results show that, changing different single parameters, the time taken for the steady backwater temperature is different, but relatively short;and if multiple parameters are changed, the time will be longer. Referred to the thermal balance test, the simulation results are validated and provide a basis for the intelligent control of the cooling system.     

Design of Uncooled Thermal Imaging Systems Operating at Multiple Temperatures

The reasons why thermal imaging systems consume power are analyzed, and a low power consumption design scheme is presented for the thermal imaging systems operating at multiple temperatures. The relation between the response performance of α-Si microbolometer detector and its operating temperature is studied by means of formulas of mierobolometer detector＇s noise equivalent temperature difference （NETD） and detectivity. Numerical analysis based on true parameters demonstrates that the detectivity decreases slightly and NETD increases slightly when operating temperature rises, which indicates that α-Si microbolometer detector has approximately uniform response in a wide operating temperature range. According to these analyses, a thermal imaging system operating at multiple temperatures is designed. The power of thermoelectric stabilizer （TEC） is less than 350 mW and NETD is less than 120 mK in the ambient temperature range of - 40℃- 60℃, which shows that this system not only outputs high-quality images but consumes low power.     

Joint Maintenance Policies for a Stored System with Two Units

Failure of a stored system can only be detected after inspection and its reliability can be resumed by replacement of failed components. A maintenance policy of combining periodic inspection and preventive replacement is proposed to improve its availability. To coordinate component replacement and spare provision, an ordering policy of （0, 1） is consid- ered jointly. Thus, the joint maintenance policy contains inspection, replacement and spare provision. A programming model based on the joint maintenance policy is established, whose objective function is average expected cost, containing maintenance cost and inventory cost, and the constraint is system availability. Applying renewal theorem, the perfor- mance indexes are deduced under the condition that the stored system obeys the common life distribution. Numerical examples are given for a stored system with two different units, where unit 1 probability degrades with time and unit 2 probability degrades at each test. The effect of reliability parameters on the policies is discussed. The results indicate that the joint policy is very close to the independent policy.     

Optimization of process parameters of the activated tungsten inert gaswelding for aspect ratio of UNS S32205 duplex stainless steel welds

The activated TIG （ATIG） welding process mainly focuses on increasing the depth of penetration and the reduction in the width of weld bead has not been paid much attention. The shape of a weld in terms of its width-to-depth ratio known as aspect ratio has a marked influence on its solidification cracking tendency. The major influencing ATIG welding parameters, such as electrode gap, travel speed, current and voltage, that aid in controlling the aspect ratio of DSS joints, must be optimized to obtain desirable aspect ratio for DSS joints. Hence in this study, the above parameters of ATIG welding for aspect ratio of ASTM/UNS S32205 DSS welds are optimized by using Taguchi orthogonal array （OA） experimental design and other statistical tools such as Analysis of Variance （ANOVA） and Pooled ANOVA techniques. The optimum process parameters are found to be 1 mm electrode gap, 130 mm/min travel speed, 140 A current and 12 V voltage. The aspect ratio and the ferrite content for the DSS joints fabricated using the optimized ATIG parameters are found to be well within the acceptable range and there is no macroscopically evident solidification cracking. Copyright ？ 2014, China Ordnance Society. Production and hosting by Elsevier B.V. All rights reserved.     

Modeling of Testability Requirement Based on Generalized Stochastic Petri Nets

Testability design is an effective way to realize the fault detection and isolation. Its important step is to determine testability figures of merits （TFOM）. Firstly, some influence factors for TFOMs are analyzed, such as the processes of system operation, maintenance and support, fault detection and isolation and so on. Secondly, a testability requirement analysis model is built based on generalized stochastic Petri net （GSPN）. Then, the system＇s reachable states are analyzed based on the model, a Markov chain isomorphic with Petri net is constructed, a state transition matrix is created and the system＇ s steady state probability is obtained. The relationship between the steady state availability and testability parameters can be revealed and reasoned. Finally, an example shows that the proposed method can determine TFOM, such as fault detection rate and fault isolation rate, effectively and reasonably.     

Study on Multi-objective Optimization of Airbag Landing Attenuation System for Heavy Airdrop

A finite element model of velticle mad its alrbag landing attenuation system is established mad verified experimentally. Two design cases are selected to constrain the ah-b ag design for extreme landing conditions, wfiile the height and width of ah-bag and the area of vent hole are chosen as design variables. The optimization is forced to compromise the design variables between the conflicting requirements of the two extremes. In order to optimize the parameters of ah-bag, the multi-dimensional response surfaces based on extended Latin hypercube design and radial basis function are employed instead of the complex filtite element model. Pareto optimal solution sets based on response surfaces are then obtained by multi-objective genetic algotitlml. The results show the optimization method presented in tfiis paper is a practical tool for the optimization of ah-bag landing attenuation system for heavy airdrop.     

Research on Collaboration Decision Design of Complex C2 System

The design of collaboration decision of C2 system is one of the puzzles which dicision science studies in complex system. To solve the contravention between the theory of collaboration decision design and development requirement in distributed C2 system, three-stage design approach is proposed to-research coherence and optimization by which decisionmaker carries out decision regulations. First, getting information and decision process are described; decision indexes and regulation models of collaboration are established. And then, a test circumstance is designed and established for measuring various decision-maker＇s capabilities of carrying out decision regulation by simulation and getting their load capability parameters. Finally, the obtained parameters from the experiment are disposed and substituted into the original models for proving the coherence of decision regulations. As a result, it is feasible for three-stage approach to design collaboration decision, and decision regulations can satisfy various decision-maker requirements.     

Design of Neural Network Variable Structure Reentry Control System for Reusable Launch Vehicle

A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of coupling among the channels and the uncertainty of model parameters are solved by using the method.High precise and robust tracking of required attitude angles can be achieved in complicated air space.A mathematical model of reusable launch vehicle is presented first,and then a controller of flight system is presented.Base on the mathematical model,the controller is divided into two parts：variable-structure controller and neural network module which is used to modify the parameters of controller.This control system decouples the lateraldirectional tunnels well with a neural network sliding mode controller and provides a robust and de-coupled tracking for mission angle profiles.After this a control allocation algorithm is employed to allocate the torque moments to aerodynamic control surfaces and thrusters.The final simulation shows that the control system has a good accurate,robust and de-coupled tracking performance.The stable state error is less than 1°,and the overshoot is less than 5%.     

液压排雷机械手作业系统的运动学分析

通过对机械手作业系统的运动学分析,按照D-H坐标系的建立原则,确定系统的广义坐标,选取机构中的旋转副和移动副作为关节变量,推导出各关节的广义变换矩阵,得到了机械手指端的运动学方程,求出机械手运动学的正解.经计算机模拟得到机械手作业系统的工作几何参数和主要技术指标,结果表明其能够达到完成作业任务规划的要求.该研究为机械手应用时的优化结构参数提供了理论基础,从而也论证了机械手运用于液压挖掘机平台上的可行性.     

基于知识规则的2.4 m 风洞控制开车参数自动生成专家系统

针对2.4 m风洞控制开车参数往往取决于人工经验、难以准确给定控制参数的问题,开发一种基于知识规则的控制开车参数自动生成专家系统.首先简要介绍了2.4 m风洞核心控制系统和专家系统的基本架构,然后详细介绍了开车参数自动生成专家系统的设计方法.采用C++Builder语言开发了一套软件,实现了2.4 m风动主要控制执行机构预置位置参数的自动生成.实际的应用结果表明:该系统具有适应能力强、覆盖范围广、可靠性高等特点.     

基于视觉的机械手臂自主抓物的实现

双目视觉可以获得目标物体的三维坐标信息，根据三维坐标，控制器对机械手臂的运动学进行分析，求解出运动学逆问题的解，并根据解来控制机械手臂各个关节，实现机械手臂的自主抓物。在整个控制系统中，采用递阶、分层的系统结构，可较好地完成机械手臂的控制要求。     

细长腔体检测机器人设计研究

对现有人力不可达腔体的几种机器人检测方式进行比较,针对安装有精密零件的某航天器腔体设计了一台检测机器人XN-600-3.该机器人基于柱坐标系设计,视觉系统固定在一条细长机械臂末端,由两自由度关节驱动深入腔内进行检测。该机器人的大部分功能集中在机座内,即机械臂的全部驱动件移至机座内,悬臂部分负载最轻刚度最高,执行系统拥有最优的动态性能。试验证明该机器人具有长行程、高刚度、大回转角、小回转半径的优点,检测过程中视觉系统振幅最大为0.6 mm.通过机械臂末端的高精度摄像机捕获图像,该机器人可用于腔内装配尺寸或焊接质量等检测项目。     

四旋翼碟形自主水下航行器运动方程建立与流体特性仿真研究

四旋翼碟形自主水下航行器（AUV）是一种新型水下航行器。为研究此航行器的流体动力特性,建立了四旋翼碟形AUV的三维模型,并定义了参考坐标系和广义特征参数;在其体坐标系中根据动量和动量矩定理,建立了广义参数定义的AUV六自由度动力学方程和运动学方程;采用计算流体力学方法,基于Ansys CFX流体分析软件,在的0°~90°攻角范围内,对航行器运动过程中的流体动力特性进行了仿真研究,并绘制了其特性曲线。仿真结果表明：在0°~15°攻角范围内,航行器具有较低的流体阻力,适宜做定深运动;在30°~50°攻角范围内,航行器具有良好的升力特性,适宜完成曲线潜浮运动。     

基于运动学分析的装甲车辆驾驶操纵舒适性研究

运用人体运动学理论和方法，以国军标和相关国标为依据，建立了装甲车辆驾驶员的运动学模型，并以某型坦克为例，对装甲车辆驾驶舱操纵装置的操纵舒适性进行了分析，其结果可为装甲车辆驾驶舱操纵装置的合理布局提供借鉴．     

基于Kane方法的波浪驱动水下航行器动力学模型建立

基于多体系统动力学理论,定义并选取适当的坐标系和广义坐标,对波浪驱动水下航行器多体系统进行运动学分析,得到各部分的速度和加速度;基于Kane方法进行动力学分析,计算各部分的偏速度和偏角速度,进而求得系统的广义主动力和广义惯性力。将系统的广义惯性力和广义主动力代入Kane方程中,得到波浪驱动水下航行器多体系统动力学模型。在受力分析中,不仅考虑了惯性力、惯性力矩、重力和浮力以及流体动力,还重点分析了波浪力和多体系统的附加质量力。对波浪驱动水下航行器进行了运动仿真,仿真结果显示航行器航行稳定,所建立的模型是有效的。     

导弹发射车起竖工况力学特性分析

利用微机有限元ＳＡＰ６软件，对某导弹发射车使用中的一个重要工况－起竖工况的整体力学特性进行分析，建立了导弹发射车起竖工况整体有限元模型，利用欧拉角确定了发射筒起回转轴转动时的相对坐标系。     

迫击炮供输弹机械手结构设计和动力学分析

针对传统迫击炮自动化程度低、战场生存能力差等弱点,设计了用于120 mm迫击炮的供输弹机械手,实现3～4发/每分钟的射击速度.采用ADAMS软件进行机械手的动力学仿真,得到包括炮弹运动参数、机械手振动变形以及关节驱动等关键数据.