30mm半穿甲弹斜侵彻陶瓷/钢复合装甲的弹着角效应研究

设计了30mm半穿甲弹斜侵彻陶瓷/钢复合靶的弹道试验,采用高速摄像记录了弹靶作用过程,研究了弹着角、弹丸位移以及背板变形挠度的图像测量方法,通过仿真验证了该方法的可行性与准确性.基于高速摄像序列图像对弹靶作用过程进行了测量分析,结合试验数据研究了弹着角对半穿甲弹侵彻效能的影响.结果表明:弹着角导致弹丸受靶板的不对称阻力作用,侧向力及侧向力矩使得弹丸在侵彻过程中不断偏转,表现为侵彻路径呈曲线;在相同速度条件下,随着弹着角的增大,侵靶时间延长,背板变形挠度减小,侵彻效能降低.     

微小型无人机遥感图像应用

通过给微小型无人机加装数码相机和微型INS姿态测量系统,可以同时获得对地面的遥感图像和当时无人机的姿态数据.根据传感器构像方程和几何畸变校正理论,对拍摄的图片进行几何校正.通过图像融合拼接,给出了目标地区的大面积数字影像图,最后给出了局部实验结果.     

飞机图像导航数据库系统的设计与开发

运用图像导航原理,设计并实现了一套飞机图像导航数据库系统.系统将导航所需的信息和若干地区的地面图预先存放在数据库中的特定位置.用户只需在系统的可视化界面中进行少量的操作,该系统就能够在飞机航行的过程中实时地显示拍摄到地面图像,并将该图像与数据库中的相关图像进行特征匹配,从而获取并提供给用户飞机当时的位置、航速快慢及航向误差等导航信息.     

基于相位相关和自适应阈值的图像亚像素配准

针对图像的亚像素配准问题,提出了一种基于相位相关和自适应阈值技术来计算图像间平移参数的方法.先通过传统的相位相关技术得到图像间的整数平移参数,接着引入由整数平移参数自适应确定的阈值来消除相位相关矩阵的主导奇异向量中相应的高频部分,最后使用主导奇异向量剩下的部分来估计非整平移参数.实验结果证实了这一方法具有较高的配准精度和鲁棒性.     

基于FAHP的岸防炮兵雷达作战效能评估分析方法

针对岸防炮兵雷达的特点和作战任务,从探测能力、定位能力、数据处理能力、目标识别能力、抗干扰能力、可用性、可靠性和生存能力8个指标层,建立岸防炮兵雷达作战效能评估的层次结构体系,并确定了指标体系综合指标的随机性和模糊性,运用模糊层次分析法对雷达效能进行综合评估,给出了确立各因素权重的方法.为该雷达作战使用提供了辅助决策的依据.     

红外成像型空空导弹目标自动识别技术

针对红外导弹和红外诱饵弹的对抗,构建了红外导引头图像探测器的透视投影几何模型.基于模型证明了飞机和目标在不同距离和相对飞行速度下,成像序列中相邻两帧图像间飞机目标的相似性,并且提出了适合导弹的目标快速识别算法,该算法是基于当前帧图像与前一帧图像的目标特征匹配的.最后以实测的飞机及诱饵红外图像数据对文中提出的算法进行了仿真,仿真结果表明了算法对目标识别是可行和有效的,并且能够满足较高实时性的要求.     

层次分析法在反坦克导弹阵地选择中的应用

反坦克导弹是未来高技术战争中不可或缺的反装甲兵种,特别是在渡海登岛作战中,先头抢滩登陆部队能否巩固和扩大登陆场地,很大程度取决于登陆部队反装甲力量的运用.在此过程中,反坦克导弹分队的阵地选择极其重要,运用层次分析法建立反坦克导弹阵地选择的递阶层次模型,通过计算,确定反坦克导弹阵地选择的最佳方案通过组合一致性检验,选择地形单元C_1为反坦克导弹阵地,作为最终的决策依据.     

Consequence of reinforced SiC particles and post process artificial ageing on microstructure and mechanical properties of friction stir processed AA7075

Friction stir processing and post process artificial ageing was successfully carried out on AA7075 with and without reinforcement of SiC particles producing defect free processed zone with uniform distribution of filler material. Effect of SiC particle reinforcement and artificial ageing times on the microstructural modifications was characterized using optical and electron microscopy, electron backscattered diffraction and X-Ray diffraction. Hardness, impact and wear tests were carried out to investigate mechanical behaviour before and after processing. Reinforcement of SiC particles during FSP and subsequent age hardening treatment brought about nearly twofold increase in hardness and impact toughness values by the combined effect of grain refinement, Zener pinning, dispersion strengthening and precipitation hardening. Significant improvement in wear resistance in terms of wear loss was also observed after processing compared to the reference material AA7075-T6. Fractured surface of post FSP age hardened AA7075 alloy exhibited features of ductile fracture during Charpy impact test.     

Optimal production ramp-up in the smartphone manufacturing industry

Motivated by challenges in the smartphone manufacturing industry, we develop a dynamic production ramp-up model that can be applied to economically satisfy nonstationary demand for short-life-cycle products by high-tech companies. Due to shorter life cycles and more rapid evolution of smartphones, production ramp-up has been increasingly critical to the success of a new smartphone. In the production ramp-up, the key challenge is to match the increasing capacity to nonstationary demand. The high-tech smartphone manufacturers are urged to jointly consider the effect of increasing capacity and decreasing demand. We study the production planning problem using a high-dimensional Markov decision process (MDP) model to characterize the production ramp-up. To address the curse of dimensionality, we refine Monte Carlo tree search (MCTS) algorithm and theoretically analyze its convergence and computational complexity. In a real case study, we find that the MDP model achieves revenue improvement by stopping producing the existing product earlier than the benchmark policy. In synthetic instances, we validate that the proposed MCTS algorithm saves computation time without loss of solution quality compared with traditional value iteration algorithm. As part of the Lenovo production solution, our MDP model enables high-tech smartphone manufacturers to better plan the production ramp-up.     

考虑非线性退化与随机失效阈值的剩余寿命预测

针对广泛存在的非线性退化设备,现有方法尚未考虑随机失效阈值对剩余寿命预测结果的影响。因此,通过对设备性能退化过程进行分析,提出了一种综合考虑非线性退化与随机失效阈值的剩余寿命预测方法。基于Wiener过程构建了考虑个体差异与测量误差的非线性退化模型;基于卡尔曼滤波算法建立状态空间模型以实现对退化状态的在线更新;基于极大似然法估计失效阈值分布系数估计方法,得到随机失效阈值的概率分布;基于随机失效阈值推导出剩余寿命的概率分布,实现对剩余寿命的在线预测。算例研究表明,所提方法可以有效地提升剩余寿命预测的准确性,具备一定工程应用价值。