考虑环境复杂度的机器人路径双向蚁群规划

为了减少机器人的路径长度、提高路径平滑性，提出了基于配对双向新型蚁群算法的路径规划方法。介绍了栅格环境模型的建立方法；给出了基于改进K-means的环境复杂度聚类方法，实现了以复杂度为标准的环境分区；将环境复杂度作为新型启发信息引入到蚁群算法中，引导蚂蚁选择简单环境区域。借鉴蚂蚁的双向搜索思想，提出了配对双向搜索的新型蚁群算法，并将该算法应用于栅格环境的路径规划。经仿真验证可以看出，与传统蚁群算法、文献[12]算法比，配对双向新型蚁群算法的路径长度最短、拐点数量最少、收敛时迭代次数最少，验证了这里算法在路径规划中的优越性。     

面向复合地图的移动机器人分层路径规划

针对传统路径规划方法在部分未知复杂大场景环境下搜索空间大、效率低、避障成功率不高等问题,提出一种基于拓扑-栅格-度量复合地图的移动机器人分层路径规划方法。首先将机器人作业环境描述为栅格地图并划分为多个栅格化的子区域,以子区域为关键节点进行位置关系抽象从而获得拓扑架构,并对局部栅格区域进行精细化描述,构建拓扑-栅格-度量的复合地图。其次,在不同地图层级上分区域搜索机器人路径,在拓扑地图上采用Floyd算法规划子区域之间的区间路径,面向栅格地图提出搜索子区域内部路径的改进A^*算法,通过引入扩展点筛选策略、双向搜索机制、路径冗余点剔除技术提高路径规划的效率与质量,并拼接各段区间路径和内部路径生成全局优化初始路径。最后,针对部分未知场景中的动态障碍物,在度量地图上提出基于深度强化学习架构的动态避障路径规划方法,利用价值分类经验回放机制提高样本的利用率和模型训练的效率。实验结果表明,所提方法有较高的搜索效率和避障成功率,生成的路径兼具安全性和平滑性。     

基于粒子群优化算法的小型足球机器人路径规划

为了解决足球机器人无法躲避动态障碍物和容易陷入局部极值的问题,在深入研究粒子群优化算法的基础上,提出了采用栅格法与粒子群优化算法相结合的路径规划算法。首先采用栅格法对小型足球机器人工作环境构造模型,再利用改进的粒子群优化算法进行最优路径搜索。该算法实现简单,收敛速度快,不易陷入局部极值,不仅能够满足足球机器人实时动态的路径规划要求,而且能满足不同环境下的路径规划要求。仿真实验表明,该方法可以很好地应用于足球机器人的路径规划中。     

动态环境下移动机器人路径规划的改进蚁群算法

研究动态环境下移动机器人路径规划问题,采用栅格法对机器人工作空间进行建模,在使用蚁群算法进行全局路径搜索过程中引入人工势场的概念,使蚂蚁对最优路径更加敏感;机器人针对动态环境中可能出现的不同类型障碍物分别执行不同的避障策略;同时提出一种最优路径预测模型用于预测在避障过程中是否出现新的最优路径。算法结合人工势场法和蚁群算法的特点,将全局路径规划与局部路径规划相融合以提高路径搜索的效率。仿真结果验证了该算法的有效性。     

改进灰狼优化算法在特征栅格地图上的路径规划

针对灰狼优化算法求解移动机器人路径规划易陷入局部最优且效率低的问题,本文提出一种改进灰狼优化算法在特征栅格地图上的路径规划方法。首先,对灰狼优化算法进行改进,引入根据具体要求调节算法的全局搜索和局部搜索的调节因子,并引入动态权重和游走策略以提高算法的收敛速度和避免局部最优的能力;其次,提出一种建立特征栅格地图的新方法,加快了特征栅格的确定;最后设置远距离特征栅格和可视步长,简化了邻接矩阵的建立。仿真实验结果表明,本文算法相比于其它算法在标准测试函数和路径规划问题中,都有更优的结果。在此基础上,通过建立特征栅格地图,有效地加快了改进算法在路径规划问题上的求解速度。     

月面探测器路径规划优化算法研究

针对复杂环境下的月面探测器路径搜索困难的问题,建立多约束的栅格地图模型,研究了一种改进的蚁群算法用于全局路径规划方法.在蚁群算法中加入了参数自适应调整和双向搜索并行策略以提高蚂蚁搜索路径的成功性,并对路径进行了拐角处理,使规划的全局路径更加平滑、安全,使探测器有效地在大规模地图里避开障碍物.仿真试验结果表明,该方法结合...     

基于改进蚁群算法的巡检机器人避障路径规划方法设计

针对机器人进行避障路径规划时存在收敛速度差、规划路径长、迭代次数多以及规划时间长的问题,提出基于改进蚁群算法的巡检机器人避障路径规划方法。首先使用栅格法划分巡检机器人工作环境,通过对像素矩阵等指标的分析,构建栅格地图模型;基于人工势场法提出蚁群路径规划算法,使蚁群适应子空间的搜索;最后在模型中利用该算法,寻找该模型的最佳路径。实验结果表明,运用该方法进行路径规划时,收敛速度高、规划路径短、迭代次数少以及规划时间短。     

蚁群遗传算法在移动机器人路径规划中的综合应用研究

针对基本蚁群算法在机器人路径规划搜索初期盲目性大、效率低以及其搜索后期容易陷入局部最优等缺陷,把遗传算法引入到蚁群算法中,提出了基于蚁群遗传算法的移动机器人路径规划方案,在栅格环境下对移动机器人路径规划方案进行仿真测试,仿真结果表明该方案能减少蚁群算法搜索初期的盲目性、缩小最优路径的查找范围,提高搜索最优路径的效率。     

蜂巢栅格下机器人导航路径的动态分组蚁群规划

为了减少机器人导航路径的长度和算法运行时间,同时提高算法规划稳定性,提出了蜂巢栅格环境下的动态分组蚁群算法规划方法。分析了方形栅格四叉树和八叉树工作模式的弊端,提出了改进蜂巢栅格的环境建模方法,蜂巢栅格避障时的有效路径比、安全性、转弯角大小、对圆形障碍物覆盖的有效面积比等多个角度均优于传统栅格。参考猫群算法的分群思想将蚁群分为跟踪蚁和搜索蚁,提出了动态分组蚁群策略和信息素的自适应扩散策略,从而给出了动态分组蚁群算法的执行步骤。经过算法的多样性和规划性能仿真分析,动态分组蚁群算法的路径多样性在迭代过程中保持较高水平,在相同环境下动态分组蚁群算法规划的最优路径长度比ACS蚁群算法减少了9.99%,搜索到最优路径时的迭代次数远远小于ACS蚁群算法,且从最优路径长度和迭代次数标准差看,动态分组蚁群算法稳定性好于ACS蚁群算法。     

基于栅格地图-蚁群算法的机器人最优路径规划

通过栅格法建立栅格地图作为机器人路径规划的工作环境,采用蚁群算法作为机器人路径搜索的规则。将所有机器人放置于初始位置,经过NC次无碰撞迭代运动找到最优路径,到达目标位置。为防止机器人在路径搜索过程中没有达到最大迭代次时路径大小已不发生变化而陷入局部最优,则通过对各路径上的信息素进行增减来使机器人路径搜索跳出当前值,继续搜索,直到迭代完毕,获得最优路径。     

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.