采用逐次正交化法的最优分布式Kalman滤波器

为解决大系统中应用整体式Kalman滤波遇到的非实时性难题,本文提出一种能保持最优的分布式Kalman滤波计算方法——逐次正交化法。这是一种适合多微机并行计算的最优算法,确保滤波的“实时性”,优于一般次优分布式Kalman滤波器。     

羊毛精纺织物服用性能优选的多属性模糊决策

本文应用多属性目标决策的方法,评判不同规格毛织面料的"满意度",客观地提供一个重要的优选辅助依据。     

双层多目标规划若干问题的研究

研究了下层决策者无关联的双层多目标规划问题，在不同偏好意义下，给出了各自解的定义，讨论了线性双层多目标规划问题。     

结构优化中的混合变量应力约束近似方法

提出一种处理结构优化应力约束的新近似方法，以往一般直接对应力约束按设计变量近似，本文用近似内力间接近似应力约束以得到更高的近似质量，根据对内力和设计变量关系分析，提出了内力按混合变量一阶泰勒展开的高捏近似方法。近似优化问题用约束变尺度法求解，最后按出了几个典型例题。结果表明该方法简单，有效，可靠。     

基于参数化模型和遗传算法的复合材料加筋壁板结构选型优化研究

针对复合材料加筋壁板的结构优化选型问题,采用辅助层压板和添加极小弹性模量材料的复合材料加筋壁板有限元建模方法,应用PATRAN/NASTRAN的参数化建模功能和遗传算法相结合的复合材料加筋壁板的优化方法,对5种复合材料结构形式进行了从2000N/mm到6000N/mm压缩载荷下的结构优化分析。结果表明,当载荷小于4500N/mm时,最有效的加筋壁板结构型式为J型;当压缩载荷大于4500N/mm时,最有效的加筋壁板结构型式为I型。     

Suggestion for aircraft flying qualities requirements of a short-range air combat mission

Owing to the lack of a direct link with the operations in short-range air combat,conventional aircraft flying qualities criteria are inappropriate to guide the design of a task-tailored flight control law.By applying the mission-oriented flying qualities evaluation approach,various aircraft with different control law parameters are evaluated on a ground-based simulator.This paper compares the evaluation results with several conventional flying qualities criteria,and discusses the appropriate parameter combination to reflect the flying qualities requirements of short-range air combat,The comparison and analysis show that a short-range air combat mission requires a higher minimum short period mode natural frequency and a smaller maximum roll mode time constant,and allows a lower minimum pitch attitude bandwidth and a higher maximum short period mode damp ratio than those of conventional flying qualities criteria.Furthermore,a combination of the pitch attitude bandwidth,the pitch attitude magnitude at the bandwidth frequency,and the pitch attitude transfer function gain can define the flying qualities requirements of short-range air com bat.The new metric can successfully predict the flying quality levels of aircraft in a short-range air combat mission.     

Influence of TiB2 particles on machinability and machining parameter optimization of TiB2/Al MMCs

In situ formed TiB₂ particle reinforced aluminum matrix composites (TiB₂/Al MMCs) have some extraordinary properties which make them be a promising material for high performance aero-engine blade. Due to the influence of TiB₂ particles, the machinability is still a problem which restricts the application of TiB₂/Al MMCs. In order to meet the industrial requirements, the influence of TiB₂ particles on the machinability of TiB₂/Al MMCs was investigated experimentally. Moreover, the optimal machining conditions for this kind of MMCs were investigated in this study. The major conclusions are: (1) the machining force of TiB₂/Al MMCs is bigger than that of non-reinforced alloy and mainly controlled by feed rate; (2) the residual stress of TiB₂/Al MMCs is compressive while that of non-reinforced alloy is nearly neutral; (3) the surface roughness of TiB₂/Al MMCs is smaller than that of non-reinforced alloy under the same cutting speed, but reverse result was observed when the feed rate increased; (4) a multi-objective optimization model for surface roughness and material removal rate (MRR) was established, and a set of optimal parameter combinations of the machining was obtained. The results show a great difference from SiC particle reinforced MMCs and provide a useful guide for a better control of machining process of this material.     

基于自适应径向基网络的舰船RCS统计特征识别方法

文章采用舰船RCS频域起伏序列的均值、标准差为识别特征向量,利用提出的基于样本密度的自适应径向基网络,进行舰船分类识别研究。自适应径向基网络采用改进的自适应PSO方法估计样本密度最优邻域半径,实现径向基网络中心的自适应选择。改进的自适应PSO方法采用能反映样本聚类特点的BWP指标为适应度评价函数,采用快慢结合的高斯自适应惯性权重调节策略,提高了最优样本密度邻域半径的搜索速度和精度。实验结果表明,自适应径向基网络能自适应获得径向基网络最优识别率对应的RBF中心及其位置分布,减少了对建模人员经验的依赖,提高了反舰导弹对舰船类型的识别分类能力。     

An equilibrium multi-objective optimum design for non-circular clearance hole of disk with discrete variables

An Equilibrium Multi-objective Optimization Model(EMOM) with self-regulated weighting factors has been proposed for the optimum design of non-circular clearance hole on the front flange of turbine disk. In the ‘‘equilibrium design", both the stress decrease around the hole and the least hole's profile variation are considered, which balances two ambivalent design goals. Specific discrete variables are applied to realize the standardization design in the optimization process, in which a Surrogate Genetic Coding Algorithm(SGCA) is introduced, and a special check module is used to get rid of repeated fitness evaluation of the samples. The method offers an equilibrium design for the non-circular clearance hole of the turbine disk with great accuracy and efficiency.     

一种卫星信道的反馈优化接入机制

提高卫星信道资源利用率，探索高效可行的端站接入机制是卫星通信发展亟待解决的问题之一。当前卫星通信DVB-RCS标准基于带宽预先规划的接入机制与端站随遇接入的需求矛盾凸显，因此提出一套信道反馈优化接入机制，综合考虑各端站数据业务需求，在不改变原有协议信令特征的基础上，探索性地引入谦虚度激励方法，创造性地构造动态协商反馈模型并加以求解，达到提高端站接入数量、满足随遇接入需求、提升信道利用效率、最大化整体带宽通信业务效益的目的。通过试验验证，带宽分配反馈优化机制比传统模式提高近1倍接入率，最大端站数接入时算法耗时约只有0.67s，可为卫星信道使用提供技术参考。