基于改进蚁群算法的FMS工艺路线优化配置

针对基于CON模型的FMS工艺路线优化问题提出了一种改进的蚁群算法.蚁群算法的特点表明它适合于求解FMS工艺路线优化配置这类非线性约束复杂优化问题.本文充分利用了蚁群算法在求解该类问题方面的优势,通过融合了网格法的蚁群算法实现了将蚁群算法用于求解多变量连续函数优化问题.针对蚁群算法自身存在的容易陷入局部最优等问题,提出了引入交叉算子来改进算法的性能.     

乌鸦搜索算法的改进及其在工程约束优化问题中的应用

针对工程约束优化求解困难且存在优化结果不符合约束等问题,本文研究了一种元启发式算法——乌鸦搜索算法(CSA).系统介绍了乌鸦搜索算法的基本原理、优化步骤以及与其他优化算法相比的特点.并针对该算法在求解复杂优化问题时的不足,引入动态感知概率、莱维飞行策略以及变异更新机制,提出了CSA的改进算法(MCSA).实验测试证明,MCSA在搜索精度、稳定性和搜索效率方面表现优秀.最后,针对约束优化问题,将可行性优势(FAD)准则融入MCSA,构建了约束处理机制,通过3个工程约束实例验证了MCSA的可行性与优越性.     

加工装配式流水车间节能调度建模与优化

为解决具有加工装配一体化的流水车间节能调度问题,以加工机器最小能耗为优化目标,建立加工装配式流水车间节能调度模型。该模型将装配线视为具有特殊约束的加工生产线,再结合考虑车间工件工序、装配工序、装配子件加工等约束条件。分别针对简单和复杂装配约束的问题,采用混合差分进化算法求解最小能耗下工件调度方案,并与自适应差分算法对比。实验结果证明了混合差分进化算法求解该问题的有效性。     

按传动角优化曲柄滑块机构的约束粒子群算法

建立了偏置曲柄滑块机构工作行程最小传动角最大化问题的约束优化设计模型,提出了处理该模型中约束条件的自适应罚函数法.由于粒子群算法具有简单、高效的特点,因而应用该算法求解机构约束优化问题的全局最优解.给出了数值实例,并通过与已有结果的比较来表明新方法的有效性和稳健性.     

车削加工工艺参数优化

针对车削加工中的约束优化问题,建立以切削速度v和进给量f为优化变量、以加工成本最小为目标的约束优化设计模型.提出了改进约束处理的自适应罚函数法和一种改进差分进化(Improved Differential Evolution,IDE)算法.应用IDE算法求解切削参数约束优化问题的全局最优解.给出了数值实例,通过与已有结果的比较,表明结合约束处理的IDE算法的有效性和稳健性.     

基于改进蜻蜓算法的斗轮取料机多目标优化

针对斗轮取料机系统能耗高、重量大、制造成本高、设计变量多等特点,提出一种改进的蜻蜓算法用以求解斗轮取料机的多目标优化问题.提出的改进蜻蜓算法基于自然现象和物理现象,采用空气阻力和库仑力混合组成的策略对传统蜻蜓算法进行改进,并通过测试函数验证了改进后蜻蜓算法的性能.然后建立考虑斗轮取料机可靠性和振动频率约束的质量与转动惯量的多目标优化模型,利用改进后的蜻蜓算法进行多目标求解,获得斗轮取料机的Pareto前沿解集,选择以质量与转动惯量合适权重比为例进行优化,验证开展斗轮取料机多目标优化的有效性.结果表明,优化得到的阶梯截面布局方案具有更小的质量和转动惯量值,同时可以有效避开斗轮取料机系统的共振问题,可以使斗轮取料机的性能得到有效改善,为未来的整机材料-结构-控制多学科一体化协同优化提供基础.     

基于微粒群的约束优化

针对微粒群算法在处理约束优化问题时,难以兼顾约束与优化之间关系的问题,提出了一种泛学习微粒群算法(ULPSO),通过引入微粒不可行历史最优,使得微粒的学习更具多样性和有效性,增强了算法的搜索智能.通过对常用的13个基准函敷的测试对比分析,表明该算法求解约束优化问题的计算具有快速性、稳定性和有效性.     

多体系统动力学仿真向后微分公式算法

针对多体系统动力学仿真中需要求解DAEs形式运动方程的问题,提出基于向后微分公式的DAEs算法.将已有的求解指标一3DAEs形式运动方程的NStiff算法推广到求解非完力学整系统指标一2DAEs形式的运动方程;提出了NStiff-v算法,分别求解完整约束多体系统指标一3DAEs和非完整力学系统指标一2DAEs形式的运动方程.离散过程中对约束方程进行缩放,消除了Newton-Raphson方法求解非线性方程组时由于步长较小而存在的Jacobian矩阵病态问题.通过曲柄滑块机构和Snakeboard模型两个实例,比较NStiff算法和NStiff-v算法的结果来验证算法的有效性,并比较了效率.算例说明算法求解DAEs时具有二阶精度.     

基于遗传模拟退火融合算法的船舶分段装配序列优化

针对复杂船舶分段装配序列规划问题,提出基于遗传模拟退火算法的分段装配序列规划求解方法,综合考虑分段装配中的工艺约束和几何约束,建立以分段装配所需时间和消耗成本为优化目标的问题模型,并为模型求解设计了遗传模拟退火融合算法,将模拟退火算法的局部搜索能力与遗传算法的快速全局搜索能力相结合,达到快速收敛到全局最优解的目的.通过实例验证了该算法的有效性.     

一种复杂项目调度问题的混合智能算法

针对有资源约束的项目调度问题模型的不足,调研了企业需求,提出了带有预约时间窗口约束的项目调度模型,并针对该类模型的特点分析了原有算法存在的问题,将分枝定界算法与启发式算法相结合,提出了一种解决该类问题的混合智能算法.仿真结果表明,该算法的优化效果明显优于其他算法.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.