约束总体最小二乘空间配准算法

相对于单个雷达而言,组网雷达能显著提高其融合系统的性能,但是在随机误差较大情况下,由于空间配准精度往往较低,其融合性能会显著下降.在忽略模型线性化误差的情况下,分析出这一缺点出现的原因是量测方程的系数矩阵中存在误差,进而利用系数矩阵误差存在统计相关性的特点,提出一种基于地心地固坐标系(ECEF)的约束总体最小二乘算法进...     

信息价值的战场网络战攻击威胁评估方法

通过构建信息价值综合评估模型,对C4ISR网络信息价值程度进行定量评估.然后对战场网络战攻击行为进行分析,将其攻击威胁量化到信息价值评估模型,通过被攻击网络信息价值的变化来衡量网络战攻击的威胁程度,从而提供了一种网络战攻击威胁的评估方法.     

重力势能锁止型外骨骼设计及其效能评价

现存的被动式外骨骼存在助力效果不明显等缺陷。基于人体步态特征,提出了将人体行走过程中的重力势能转化为人体抬腿过程中动能的原理,通过弹簧、曲柄滑块机构、棘轮棘爪机构以及链传动机构的组合,设计了一款被动式下肢机械外骨骼,并通过外骨骼动力学分析和生理消耗指数实验测试的方法进行了外骨骼性能评价。动力学分析结果表明,穿戴外骨骼后髋关节峰力矩总量降低了23.43%,髋关节做功总量降低了30.59%,初步验证了外骨骼的有效性。生理消耗指数实验测试结果表明, 穿戴外骨骼对于短距离动作转换未产生显著效果,但在长距离行走和上坡行走中分别降低了8.1%和10.4%的能量消耗。因此,该下肢外骨骼助力性能得到了验证,为相关领域的研究提供了实例化参考。     

基于多虚拟目标模型的榴弹炮炸偏修正方法

榴弹炮的传统射击修正方法是根据射击目标的高角距变及偏流不变原则完成的,该方法在通常情况下可以满足射击修正精度要求,但是在炮目距离接近最大射程,或因气象条件、弹药条件、火炮条件等数据不准确造成炸点偏离目标较远等情况下,高角距变和偏流均会产生剧烈变化,因此,传统修正方法存在较大误差.提出一种基于多虚拟目标模型的修正方法来改善这个问题,分析结果表明,该方法比传统方法修正精度更高.     

Storage life prediction under pre-strained thermally-accelerated aging of HTPB coating using the change of crosslinking density

In order to predict the storage life of a certain type of HTPB (hydroyl-terminated polybutadiene) coating at 25 C and analyze the influence of pre-strain on the storage life, the accelerated aging tests of HTPB coating at 40 C, 50 C, 60 C, 70 C with the pre-strain of 0%, 3%, 6%, 9%, respectively were carried out. The variation regularity of the change of crosslinking density was analyzed and the aging model of HTPB coating under pre-strained thermally-accelerated aging was proposed. The storage life of HTPB coating at 25 C was estimated by using the Berthelot equation as the end point of the aging life with a 30% decrease in maximum elongation. The results showed that the change of crosslinking density of HTPB coating increased with the increase of aging temperature and aging time, and decreased with the in-crease of pre-strain. Under 0% pre-strain, the relationship between the change of crosslinking density of HTPB coating and the aging time can be described by the logarithmic model with the confidence probability greater than 99%.The stress relaxation phenomenon existed under 3%, 6% and 9% pre-strained aging. The aging model considering chemical aging and pre-strain was established with the confidence probability greater than 90%. The storage life of HTPB coating was 15.2935 years at 25 C under 0% pre-strain, which was reduced by 13.9007%, 75.6949% and 89.7859% under 3%, 6% and 9% pre-strain, respectively. The existence of pre-strain has a serious impact on the storage life of HTPB coating, therefore, the pre-strain should be avoided as much as possible during the actual storage.     

基于奇异谱修正香农熵的雷达信号识别方法

针对当前雷达辐射源识别在低信噪比下识别率准确率不高,信号处理过程中难以很好保留有用信息的问题,提出了一种基于奇异谱修正香农熵(Singular Spectrum Modified Shannon Entropy,SSSE)的雷达调制信号识别方法.通过符号化聚合近似和奇异谱分析对雷达信号进行处理,求出信号的分类特征SSSE,通过分类器将处理后的信号进行分类.仿真结果显示,该方法在低信噪比范围下,仍有较高总体识别率,并且优于符号化聚合近似和奇异谱分析法.     

基于CAS理论的两栖编队作战体系能力涌现模型

研究两栖编队作战体系能力涌现机理是组建两栖编队、构建两栖编队作战体系,提升两栖编队作战效能的依据.在具体分析两栖编队作战体系复杂性的基础上,从体系多元组成相互作用、整体层次关联递进协同角度,研究两栖编队作战体系层次相干作用、功能递进关系,进而应用矢量矩阵集合工具给出其在多域组分效应、结构效应、规模效应和环境效应共同制约和塑造下的能力涌现模型.分析两栖编队作战能力涌现模型核心影响因素和信息融合特征指标.最后,得出"两栖攻击舰是两栖编队作战体系能力生成的核心要素、信息融合水平是两栖编队作战能力生成高低的突出表征"等结论和启示.     

基于拦截任务的飞机作战半径仿真研究

为解决拦截飞机作战半径计算复杂的问题,提出了一种计算作战半径新方法.定义了作战飞机作战半径、最短拦截时间和拦截线等概念;推导了拦截飞机作战半径计算模型,量化了载荷和空战意图对作战半径的影响,实现了多型飞机的作战半径估算;基于最小二乘法实现了对仿真作战半径的修正,验证了该计算方法所得作战半径,能够满足空战仿真、任务规划和效能分析的工程需求.     

Theoretical and numerical simulation study on jet formation and penetration of different liner structures driven by electromagnetic pressure

The use of a shaped liner driven by electromagnetic force is a new means of forming jets. To study the mechanism of jet formation driven by electromagnetic force, we considered the current skin effect and the characteristics of electromagnetic loading and established a coupling model of"Electric—Magnetic—Force"and the theoretical model of jet formation under electromagnetic force. The jet formation and penetration of conical and trumpet liners have been calculated. Then, a numerical simulation of liner collapse under electromagnetic force, jet generation, and the stretching motion were performed using an ANSYS multiphysics processor. The calculated jet velocity, jet shape, and depth of penetration were consistent with the experimental results, with a relative error of less than 10％. In addition, we calculated the jet formation of different curvature trumpet liners driven by the same loading condition and ob-tained the influence rule of the curvature of the liner on jet formation. Results show that the theoretical model and the ANSYS multiphysics numerical method can effectively calculate the jet formation of liners driven by electromagnetic force, and in a certain range, the greater the curvature of the liner is, the greater the jet velocity is.     

Chain damage effects of multi-spaced plates by reactive jet impact

Chain damage is a new phenomenon that occurs when a reactive jet impacts and penetrates multi-spaced plates.The reactive jet produces mechanical perforations on the spaced plates by its kinetic energy(KE),and then results in unusual chain rupturing effects and excessive structural damage on the spaced plates by its deflagration reaction.In the present study,the chain damage behavior is initially demonstrated by experiments.The reactive liners,composed of 26 wt％Al and 74 wt％PTFE,are fabricated through a pressing and sintering process.Three reactive liner thicknesses of 0.08 CD,0.10 CD and 0.12 CD(charge diameter)are chosen to carry out the chain damage experiments.The results show a chain rupturing phenomenon caused by reactive jet.The constant reaction delay time and the different penetration velocities of reactive jets from liners with different thicknesses result in the variation of the deflagration position,which consequently determines the number of ruptured plates behind the armor.Then,the finite-element code AUTODYN-3D has been used to simulate the kinetic energy only-induced rupturing effects on plates,based on the mechanism of behind armor debris(BAD).The significant discrepancies between simulations and experiments indicate that one enhanced damage mechanism,the behind armor blast(BAB),has acted on the ruptured plates.Finally,a theoretical model is used to consider the BAB-induced enhancement,and the analysis shows that the rupturing area on aluminum plates depends strongly upon the KE only-induced pre-perforations,the mass of reactive materials,and the thickness of plates.