基于遗传算法的货箱多目标优化

为了实现货箱轻量化,建立了货箱有限元模型,通过仿真与试验结果的对比,验证了有限元建模方法的准确性.利用相对灵敏度分析确定轻量化的关键部件,以货箱关键部件的板厚为变量,设计拉丁超立方试验,并基于一阶响应面函数,建立高精度的近似模型.最后,基于近似模型利用遗传算法以货箱质量最小、扭转刚度最大为目标、货箱弯曲刚度与模态性能不降低为约束,建立多目标优化模型.优化结果表明,在满足弯曲刚度的情况下,货箱质量降低19 kg,扭转刚度增大3.5%,模态性能也有提升,轻量化效果显著,为货箱轻量化研究提供思路与方法.     

多层平板屏蔽体的多目标优化设计

多层屏蔽体的设计是根据屏蔽效能等的要求来确定各屏蔽层的材料以及厚度,由于多层电磁屏蔽的屏蔽效能是入射波的角度、材料的电导率、磁导率、介电常数以及各层的厚度等的强非线性函数,因此,采用数值方法对多层屏蔽体进行设计是非常困难的。为了解决实际应用中的多层屏蔽体设计问题,提出了多目标优化设计模型,在该模型中,将屏蔽体的总质量,总价格以及总厚度作为优化目标,将多个频率的屏蔽效能作为约束条件。利用遗传算法对屏蔽体进行多目标优化设计,最后对一个三层平板屏蔽体进行了实际设计,结果表明该方法切实有效。     

弹道导弹助推段突防多目标优化设计方法

为提高弹道导弹突防能力,以导弹助推段飞行弹道和发动机为优化对象,在导弹助推段运动模型、弹道设计模型、发动机推力模型和红外辐射特性模型的基础上,提出了基于混合遗传算法的导弹助推段突防多目标优化设计方法.给出某弹道导弹助推段突防优化设计实例,优化后导弹助推段飞行时间比初始值缩短了20.4%,红外辐射强度降低了22.3%.该优化方法可有效解决导弹助推段突防方案的优化设计问题.     

基于多岛遗传算法的小型有效载荷分离装置质量优化设计

以小卫星为代表的小型有效载荷具有功能密度高,新技术吸纳快的特点,对分离姿态偏转、分离冲击、分离参数偏差等提出更高的要求,使得传统分离装置设计方法有一定局限性,容易导致分离装置结构质量偏大。本文建立了基于多岛遗传算法的分离装置质量优化数学模型,优化结果表明,在满足分离约束条件下,该方法能够有效减轻分离装置结构质量,同经验计算值相比,质量减轻约30%,节省了材料,降低了成本,具有实用价值和推广意义。     

多测速测量系统布站几何优化设计

多测速测量系统弹道参数估计的精度与其布站几何密切相关.以提高多测速测量系统弹道参数估计的精度为目的,建立了布站几何优化设计的目标函数和约束条件,采用改进的遗传算法对这一多约束条件下的非线性优化问题进行了数值计算.在算法中,对约束条件采用违反淘汰法与惩罚函数法相结合的处理方法,在保证种群质量的同时兼顾了个体的差异性;在初始种群中引入极端个体以增加其多样性,避免交叉变异陷入局部最优.最后,对多测速测量系统在布站几何优化前后采用测速样条函数定轨方法进行弹道参数估计的精度进行了实例仿真.仿真结果表明,遗传算法的布站几何优化设计对于提高多测速系统弹道参数估计的精度有效、可行.     

一种基于多目标多约束的战时抢修力量调度

为合理调度抢修力量,快速修复受损装备,在对战场抢修中抢修力量调度问题进行分析的基础上,考虑抢修任务的时间约束、逻辑约束、抢修力量的平衡度约束、抢修力量的能力、抢修花费代价等约束,建立了使作战单元战斗力恢复最大,抢修花费代价最小的多目标优化模型。同时,给出了战时作战单元战斗力指数、抢修花费代价的计算方法,设计了相应遗传算法对模型优化求解。最后,以战场抢修任务为背景,用算例验证了模型的实用性和算法的有效性。     

基于Pareto遗传算法的无后坐炮内弹道多目标优化设计

针对某中口径无后坐炮研制中的内弹道设计问题,将多目标优化的Pareto遗传算法与无后坐炮经典内弹道数学模型相结合,以最大膛压和初速作为优化设计的目标,对药室容积和发射药药量进行了多目标优化设计,提出了一种基于Pareto遗传算法的无后坐炮内弹道多目标优化方法。优化结果表明:所采用的Pareto遗传算法与内弹道相结合是可行的; 利用Pareto遗传算法,所得数个内弹道目标优化解以Pareto前沿面的形式给出,设计人员可根据需要从中选择无后坐炮内弹道的最优设计方案。     

基于抗冲击波响应的新型蜂窝夹层结构多目标优化设计

为提高某军用车辆底部防护结构对爆炸冲击波的防护性能,针对其V型底部结构,提出了一种新型蜂窝夹层结构.以降低质量、受冲击载荷后的变形挠度、加速度、增加铝蜂窝材料吸能为目标响应,设置结构中各部件的厚度、几何形状为设计变量建立多目标优化模型.结合实验设计和方差分析方法对设计变量进行参数筛选并建立优化模型的响应面;通过多目标遗传算法对响应面进行求解,得到了该优化问题的Pareto解集,从而指导该车辆底部结构改进设计;在Pareto解集的基础上使用标准边界交叉法和L2准则得到了一个理想解.仿真结果表明,优化后的新型蜂窝夹层结构较V型底部结构而言,其防护性能有明显改善,并且能大大提高防护车辆的离地间隙,这对抗爆炸结构的工程设计具有一定指导意义,且具有很大的实用价值.     

基于遗传算法的火炮反后坐装置结构多目标优化研究

大口径火炮后坐阻力和炮口扰动是影响火炮射击精度的关键因素,为了减小后坐阻力峰值和炮口扰动,基于刚柔耦合动力学理论,建立了某型火炮刚柔耦合系统动力学模型。从反后坐装置结构和总体结构的角度出发,利用ADAMS底层开发模块,结合小生境遗传算法程序建立多目标优化函数,进行火炮反后坐装置结构多目标优化设计。优化后的后坐阻力峰值及炮口扰动明显降低,表明所提出的优化方法合理可行,为火炮总体结构和反后坐装置结构的优化设计提供一定的技术参考。     

陶瓷内衬多层复合身管结构多目标优化设计

应用轴对称弹性理论建立了陶瓷内衬多层复合身管的数学模型,编写了其应力计算程序.建立了复合管多目标优化模型,将该程序集成到多学科设计优化软件iSIGHT中,应用多目标遗传算法进行优化计算,获得了问题的Pareto最优解集.对选择的优化结果用有限元分析软件MSC.Marc进行了模拟与校核.该文提出的分析方法能够切实有效地解决复杂结构的多参数优化问题.     

特种车辆电驱动系统的预测直接功率控制策略

针对脉冲宽度调制 (PWM)整流器在特种车辆电驱动系统中电流谐波及功率脉动大的问题,提出新型预测直接功率控制策略。在传统控制策略基础上设计电流观测器,通过预测控制方法估测出由系统参数失配造成的扰动并进行实时补偿,再经电流预测计算得出下一时刻的预测电流值。建立三相PWM整流器的动态模型,通过所设计的电流观测器预测电感变化后的电流值,并将其与电流的实际值作比较,经过估计系统扰动方式补偿系统误差。仿真和试验结果表明,该PWM整流器预测直接功率控制策略能有效抑制电流谐波分量以及功率脉动,实现电感参数变化条件下的正常工作,便于控制策略在特种车辆电驱动系统中实现,且能更好地提高特种车辆电源品质。     

基于响应面方法的喷水推进器进水流道多目标优化

为提高喷水推进器进水流道的流动性能,在给定进水流道出口直径D、流道高度H和流道总长度L等条件下,针对目标变量流道效率η、出口速度加权平均角θ和出口速度不均匀系数ξ,基于响应面方法对倾斜角α和过渡段半径R_T进行优化设计。采用中心复合设计法和拉丁超立方法生成35组样本点,建立目标变量随设计变量变化的响应面模型,进行局部敏感性和全局敏感性分析,发现倾斜角α对不同目标变量的影响程度均高于过渡段半径R_T. 采用多目标遗传算法对η、θ和ξ进行优化分析,得到满足条件的Pareto解。研究结果表明：优化之后,η从91.2%提高至94.1%,θ从82.5°提高至87.1°,ξ从0.152降低至0.068.     

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.     

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.     

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.     

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.     

Overview of Anti-tank Mines

First the different anti-tank mines laying possibilities are shortly summarized： hand emplaced, with mine layers, ground or helicopter relatively topographical well defined, and with cluster systems of projectiles, rockets and aircraft dispensers. Then examples of the three generations of anti-tank mines are presented：Ⅰ generation： detonating only beneath the track; Ⅱ generation： detonating beneath the track and belly; Ⅲ generation： mines with off-route actions. Weight and cost comparisons are strongly favoring the off-route Ⅲ-generation mines.     

A Finite Element Analysis on Static Strength of a Complex Section

A static finite element analysis （FEA） of an impulsive controller section is presented. The boundary condition and a part of the loads are applied. Considering the grades of the stress around the holes being large, the dense grids are adjusted accordingly. Four cases with different loads are compared, thus the influences of different loads on the section are analyzed. Numerical results show that the maximum stress of the section is lower than the strength limit of the material, and the section will not be broken with the static loads.