未知环境中基于强化学习的移动机器人路径规划

为解决未知环境中移动机器人的自适应路径规划问题,提出了一种基于Q学习算法的自主学习方法。首先设计了未知环境中基于传感器信息的移动机器人自主路径规划的学习框架,并建立了学习算法中各要素的数学模型;然后利用模糊逻辑方法解决了连续状态空间的泛化问题,有效地降低了Q值表的维数,加快了算法的学习速度;最后在不同障碍环境中对基于Q学习算法的自主学习方法进行了仿真实验,仿真实验中移动机器人通过自主学习较好地完成了自适应路径规划。研究结果证明了该自主学习方法的有效性。     

复杂环境下机器人的行为学习研究

机器人为实现在复杂环境下的探索任务,必须具有自主学习其行为策略的能力.本文将Q学习与基于案例的学习结合,实现机器人在复杂环境下的自学习能力.     

未知环境下移动机器人实时模糊路径规划

针对机器人在未知环境下避障的要求,设计了一个结合目标点位置信息和局部障碍物信息的评价函数实时导航算法,使机器人可以在无碰撞的情况下较快地到达目标点。该算法以二维激光雷达作为探测环境的主要传感器,采用基于行为的控制策略及模糊控制器技术,通过添加自由出口提高其路径搜寻的效率,最后为了验证此模糊路径规划方法进行了仿真实验。仿真实验结果表明,该算法具有良好的效果,机器人可以有效避障,且轨迹平滑、实时性好。     

光伏电池板清洗机器人定位与导航系统的开发与设计

针对目前光伏电池板清洗机器人在未知环境中感知能力差,缺乏自主规划路径和躲避障碍物能力差三方面,使用ROS机器人操作系统结合激光雷达传感器以及SLAM同步定位与建图技术来解决上述问题。采用A*和D*算法实现对机器人路径规划,以实现实时避障等功能,并通过自主开发的光伏电池板清洗机器人进行验证。结果表明：在现实环境中机器人利用激光雷达可对未知环境地图进行构建,并且机器人可按照制定路线进行移动,同时也可躲避出现在其路径之上的障碍物,验证了光伏电池板清洗机器人开发的可能性。     

基于人工情感与Q学习的机器人行为决策

提出了一种新颖的带情感权重的Q学习加权策略,并将该策略应用于虚拟机器人的行为决策.通过模拟自然情感产生机理,对害怕"进行了人工情感建模,并从自然情感所具有的生存功能角度出发,将该模型与强化学习方法相结合,与标准Q学习简单加和策略和Option分层强化学习策略进行比较的仿真实验证明了该策略具有高的成功率.该方法对于提高机器人在恶劣环境下的生存能力和自主决策能力具有很大理论意义和实际应用价值.     

基于环境点云的矿用挖掘机器人自主作业规划

针对传统矿用挖掘机难以在复杂矿岩环境下高效开采的问题,基于环境的雷达点云信息提出一种在面对复杂堆料时挖掘机器人的自主作业规划方法,以实现其连续、高效的自主化采掘任务。该方法首先利用挖掘机器人的激光雷达对复杂未知的物料环境形貌进行建模分析,通过点云信息的特点识别并筛选不同的物料堆面,然后采用多项式插值的方法对不同物料堆面的挖掘轨迹进行在线规划。结果表明,基于环境点云的自主规划方法能够使挖掘机器人在满足满斗率的条件下对不同的物料堆面实现快速有效的自主作业规划,并保证挖掘机器人连续高效的挖掘作业,对复杂工况环境下矿用挖掘机自主化的高效开采方面的研究有很大的指导意义。     

一种适用于非360°探测机器人的避障导航算法

对自主引导车辆或自主移动机器人来说,在未知环境中能避开障碍而成功到达预定的目的地是一项基本要求.Bug及其衍生算法是实现机器人在未知环境中避开障碍到达指定目的地的基于传感器的著名导航算法,它们认为机器人是平面上的一个点,具有360°障碍检测范围,具有贴着障碍物边缘绕行的能力,对通常的非360°障碍检测范围且具有物理尺寸的机器人来说,Bug类算法就不能直接应用.提出一种适用于这类机器人的改进的Bug算法,包括结合DistBug算法、VisBug算法得到较短路径的"相遇点"与"脱离点"的确定方法,基于按分段直线与速度空间法结合得到圆滑自然路径的绕行障碍物边缘算法.还提出"虚拟触角"的概念来分析利用传感器数据,机器人依靠多种"虚拟触角"实现基于传感器的改进Bug算法.编写出完整的程序实现该算法,并以Pioneer 3-AT室内机器人为对象对改进算法进行验证.结果表明,机器人可以利用提出的Bug改进算法实现未知环境下定目标点无碰撞导航.     

一种可变形机器人的避障分析

为提高未知复杂环境下移动机器人的自主避障能力,提出了一种将齿轮传动和超声波模块相结合的四连杆式变形避障机器人。该机器人通过舵机传动、连杆180°极限变形来改变自身形态以快速适应障碍的分布并躲避障碍。利用ADAMS软件及室内搭建实物环境,对直线和弯道两种避障环境进行了仿真与实操,尤其宽度窄于机器人本体的特殊障碍环境,验证了避障算法及机器人结构设计方案的有效性。     

室内移动机器人主动SLAM技术研究

为提高移动机器人自主探索室内未知环境的能力,基于实时获取的里程计和激光雷达数据,提出了一种面向室内环境的主动SLAM算法。首先利用激光雷达高精度特性,进行高频率的扫描匹配,提高了机器人定位和建图精度。同时基于实时地图,通过边界探索算法实现了机器人自主、高效遍历室内环境,并建立全局地图。鉴于室内环境通常是动态的,在全局路径规划的基础上引入局部路径规划,实现了机器人运动过程中的实时避障。使用Kobuki移动机器人平台在室内环境中进行了实验验证,实验结果表明该算法在小规模室内场景下的建图精度约为5cm,全程用时约为人为遥控方式的1.5倍。     

基于免疫强化学习机制的多机器人动态协作

利用免疫系统中T细胞对抗体的调节作用，本文提出的免疫强化学习方法以强化学习形式，动态调整抗体间相互作用系数，优化网络结构，充分利用了免疫系统的自学习、自适应和免疫记忆特性。将免疫强化学习应用于机器人系统，机器人基于行为集，在实际运行中在线学习未知环境信息，优化行为选择。在基于免疫学习的单机器人系统基础上，考虑多机器人协作性，并应用于多机器人多目标探测中。仿真验证了基于免疫学习机制的多机器人系统对未知动态环境的学习能力和动态协作的有效性。     

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.