堆垛机式密集仓储系统复合作业三维空间路径优化

为提高堆垛机式密集仓储系统的运作效率,提出混合蚁群算法,利用该算法有效地解决了复合作业三维空间路径规划问题。在堆垛机和穿梭车配置比为1∶2情况下,分析堆垛机和穿梭车在三维空间内的实际调度路径,并考虑其运动过程中的加速度建立数学模型。针对该系统复合作业的特点,设计了一种三维启发函数来改进蚁群转移概率,将遗传算法生成的初始解转变为蚁群算法的初始信息素,通过粒子群算法对蚁群算法参数进行优化,避免蚁群算法为寻求最优参数组合而进行大量盲目实验。实例分析表明,所提出的混合蚁群算法与遗传和蚁群算法相比,具有更好的全局性,能够有效地缩短密集仓储系统复合作业的时间、优化三维空间路径、提高进出库调度效率。     

基于改进蚁群算法的立体仓库三维空间路径优化

拣货作业作为在制造企业仓储系统中重要环节,其工作效率直接影响整个仓储系统的运行速度和工作成本.首先基于现有蚁群搜索算法,研究了将原有的二维平面搜索路线空间扩展到三维空间的改进蚁群算法;其次对改进蚁群算法进行仓储三维空间路径优化研究,针对现有仓库货架模型,将蚁群算法中两点间的直线路径转化成水平与垂直的折线路径将概率模型与禁忌表方法加入到改进蚁群算法,避免局部最优解的情况;最后将改进蚁群算法与其他代表性优化算法比较.实例验证结果表明,改进蚁群算法方法能有效地提高在仓储系统三维空间内路径规划的效率与速度.     

基于改进量子微粒群的轨道导引小车系统建模与优化

为提高自动小车存取系统中轨道导引小车系统的出入库作业效率,提出了一种基于改进量子微粒群的优化方法。分析了轨道导引小车系统出入库作业任务队列特征,建立了数学模型。在此基础上利用量子微粒群算法进行优化调度,并在该算法中引入高斯变异算子,克服了其容易陷入局部最优的缺点。通过仿真实验表明了方法的可行性和有效性。     

考虑碳排放的子母穿梭车密集仓储系统复合作业三维路径规划

为提高子母穿梭车密集仓储系统运作效率,对系统的复合作业三维路径规划问题进行研究。为减少复合作业过程中出入库设备的碳排放量,在其复合作业三维路径规划中考虑了碳排放成本因素,在模型中引入温室气体单位税收成本,建立了考虑碳排放成本和设备作业时间的双目标调度优化模型。在求解该数学模型中,设计了混合智能水滴算法。实例研究表明,与智能水滴算法、布谷鸟算法相比,设计的混合智能水滴算法具有更好的全局搜索能力及更快的收敛速度,能够有效地降低复合作业设备的碳排放成本,优化三维空间路径,提高出入库效率。     

双载式多层穿梭车仓储系统复合作业路径优化

为提高自动化立体仓库的运作效率,提出混合植物繁殖算法,有效地解决了双载式多层穿梭车仓储系统复合作业路径优化问题。分析了提升机和穿梭车在系统中的实际调度路径,并考虑了其运动过程中的加减速度特性建立相应的数学模型。针对该系统复合作业的特点,设计结合交叉变异算子的混合植物繁殖算法对该模型进行优化求解,将算法中的固定边界复杂交换转换为固定边界的随机乱序排列,避免算法过早收敛陷入局部最优,以此提高算法性能。通过实例分析表明,与遗传算法和基本植物繁殖算法相比,混合植物繁殖算法的运算速度更快、优化效率更高,能够有效地缩短双载式多层穿梭车仓储系统复合作业时间,提高进出库调度效率。     

改进ACO在移动机器人路径规划中的研究

针对基本蚁群算法(ACO)易陷入局部最优和收敛速度慢的特点,提出了一种在复杂静态环境下移动机器人路径规划的蚁群优化改进算法。该算法通过限制信息素的范围,扩大了搜索范围,避免了算法的过早收敛,同时还提出了一种自适应调节信息素挥发系数的改进蚁群算法方略,旨在通过自适应的调整信息素挥发系数来提高算法的全局性和算法的收敛速度。算法还利用粒子群优化算法对蚁群算法中的关键参数进行优化,从而避免了参数选择的随机性和盲目性,提高了最优路径的搜索效果。仿真结果显示,改进蚁群算法在移动机器人路径规划中的有效性和普遍应用性,在任意随机给定的环境中,算法能够迅速找出最优路径。     

基于冲突预测的多自动导引小车避碰决策优化

为有效解决路径冲突和避碰问题,提高多自动导引小车(AGV)系统的作业效率,提出基于冲突预测的多AGV避碰决策优化方法。结合图论提出一种基于顶点属性和实时位姿信息的冲突预测方法,在考虑路网全局状态的基础上建立避碰决策的数学评价模型,提出一种适用于多AGV系统避碰决策优化的改进粒子群优化算法,通过优化粒子运动的速度和方向避免优化算法过早收敛。采用融合遗传算法的变异思想为粒子引入变异操作,改善优化算法的全局搜索能力。最后通过实验测试表明,该优化方法可以有效解决多AGV系统路径冲突问题,还能缩短避碰过程中AGV的等待总时长,提高多AGV系统运行的安全性与效率。     

基于改进蚁群算法的激光切割加工路径优化研究

针对激光切割加工全局路径优化采用传统蚁群系统算法时,存在收敛速度慢、易陷入局部最优的问题,对蚁群系统算法进行了改进研究。利用激光加工图元的起点和终点信息,建立了图元等价TSP问题的数学模型,提出了通过最邻近插入算法对蚁群系统算法路径规划结果进行了再优化的改进算法;详细阐述了改进蚁群系统算法的实现步骤,分析了传统蚁群系统算法和改进蚁群系统算法的迭代次数和优化效果。研究结果表明:该改进蚁群系统算法加快了收敛速度,迭代次数减少了约30%,缩短了激光加工所走路径的总长度,并成功应用到自主开发的高速激光切割加工系统中。     

固定节点AGV系统调度方案分层优化算法研究

为优化固定节点下AGV系统任务调度等问题,提高AGV系统运转效率,提出了一种改进算法。以最小化整体作业时间为目标,通过固定节点产生路径方案,将任务调度分层为任务分配与任务排序进行分步优化,与直接优化调度的传统算法进行测试对比,改进算法的收敛速度更快,调度方案更佳,有效缩短了空载路程,实现了AGV系统调度问题的优化求解。     

一种新型混合优化算法在机器人路径规划中的应用

针对模拟退火算法收敛速度慢这一缺点，提出了一种基于模拟退火算法和复合形法相结合的新型混合优化算法，并成功应用于机器人神经网络路径规划中。该算法不仅继承了模拟退火算法能得到全局最优解的优点，又能搜索到理想的下降方向，提高了算法的收敛速度。仿真实验研究表明：这种新型混合优化算法，计算简单，收敛速度快，初值鲁棒性好。     

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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

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.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

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.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.