水陆两栖仿生海龟机器人设计与分析

针对传统机器人在水陆工作环境下运动模式转换的适应性问题,以海龟的水陆行进方式为出发点,分析了水下扑翼动作、水下转向和沉浮动作以及上岸后水翼折叠动作的实现方式,提出了一种采用扑翼传动机构、可变形自锁水翼机构、后腿机构和重心调节机构来实现水陆行进的水陆两栖仿生海龟机器人设计方案。建立了扑翼传动机构运动模型和仿生机器人整体重心仿真模型,分析了仿生扑翼运动特性并计算了固定配重安装位置。对仿生水翼进行力学分析,表明机器人能够实现可靠的水下扑翼运动。对仿生机器人关键零部件进行了流固耦合力学仿真分析和方案优化。试制了仿生机器人样机并进行了试验测试,实现了仿生机器人的基本功能。     

基于多目标遗传算法的水陆两栖可变形机器人结构参数设计方法

水陆两栖可变形机器人是一种兼具变形能力与两栖环境适应能力的新型移动机器人。在其机构设计中,结构参数直接影响该机器人在任务环境中的各项机动性能。针对水陆两栖可变形机器人工作环境复杂性和任务多变性,提出一种基于多目标遗传算法的机器人结构参数设计方法,以得到该型机器人在两栖环境中的最优的综合性能。在水陆两栖可变形机器人陆地环境和水环境中运动学和动力学模型基础上,建立两栖环境中机器人的机动性能指标函数与结构参数的映射关系,并在此基础之上构建面向水陆两栖可变形机器人的结构参数设计的多目标优化问题。利用多目标遗传算法得到该多目标机构参数设计问题的Pareto最优解集,并且通过组合赋权方法确定各目标决策属性的权重,从Pareto最优解集中得到符合设计要求的水陆两栖可变形机器人的各项机构参数最优解,进而指导机器人最终结构参数设计。根据最终得到的结构参数研制出水陆两栖可变形机器人样机Amoeba-II,并在两栖环境下进行样机的各项性能试验,最终验证了基于多目标遗传算法的机器人结构参数设计方法的有效性以及在机器人设计中的适用性。     

双摆臂履带可变形机器人结构设计与越障性能研究

为发挥履带可变形机器人最佳越障性能,保证机器人在变形过程中履带长度不变且持续张紧,将椭圆定理和椭圆规原理应用于机器人构型设计,研制了一种新式履带可变形机器人。通过引入后摆臂,丰富了机器人构型变化,机器人重心在前后摆臂转动过程中有较大程度的调节,提高机器人的越障性能。建立坡道、台阶和沟壑等典型障碍的数学模型,对机器人翻越障碍进行步态规划和运动机理分析;建立机器人越障的运动学和动力学模型,分析机器人越障的临界条件和最大数值,利用Adams对越障进行仿真实验,结果验证了理论计算值的准确性和机器人的越障性能。     

仿生鱼尾鳍推进并联机构设计

仿生尾鳍推进水下机器人的核心问题之一是推进机构的设计及其运动控制,而如何减小推进机构的体积,实现对鱼类尾鳍典型运动的精确模拟是其中的关键因素.提出一种新结构形式的两关节并联仿生尾鳍推进机构.基于该推进机构的简化模型,分析组成机构各杆件的运动规律,以及拍动中位角和各连杆长度之间的关系,对推进机构所占空间进行对比分析.提出转弯性能和机构奇异点对推进机构各杆件的约束条件.结果表明该并联结构方式可以实现转向,也减小推进机构占用空间.针对典型参数,对尾鳍机构进行运动仿真,结果肯定设计的合理性,为水下仿生机器人的尾鳍推进机构提供一种设计方案.     

一种新型的空间仿生机械腿的机构设计与研究

调查目前仿生机器人的研究现状,提出一种空间仿生机构和可变形腿运动机构。该机构具有运动灵活、自由度少、适应性强的特点。利用D-H矩阵分析法和直角坐标分析法对该机构的基本运动单元的运动学进行了理论分析,并给出了运动方程。利用SolidWorks三维造型软件进行了机构的三维建模与干涉检查,利用ADAMS软件建立了这种新型的仿生机器人的虚拟样机,进行了基本运动单元的运动学仿真。根据机构的位移矩阵变换原理,进行了轨迹的对比分析,提出可变形腿机构。     

仿生鳐鱼水下机器人的设计与仿真分析

基于鳐鱼的胸鳍波动式运动原理,设计了一台采用软体鱼鳍机构的仿生鳐鱼水下机器人。对这一机器人进行了结构建模与运动学仿真,确认鳐鱼机构可进行有效运动,鱼鳍可实现规律性波动,进而验证了仿生鳐鱼水下机器人的可行性。     

基于液压驱动的仿生推进器设计及运动学分析

MPF推进模式鱼类的高效、低扰动游动特性,逐渐受到水下机器人研究者的广泛关注。以"尼罗河魔鬼"鱼的柔性长背鳍为仿生对象,设计了一种液压驱动的模拟柔性长背鳍波动运动的仿生推进器。详细介绍了该仿生推进器的结构和工作原理,并建立了相应的运动学模型。在MAT-LAB中,根据运动学模型分析了鳍条高度、鳍面基线的不同组合下鳍面的运动效果。初步开展了该仿生推进器试验装置的试验。计算仿真和试验结果表明:液压驱动的仿生推进器运行流畅、结构和运动参数调整有效,完全可以模拟仿生对象的运动。     

小型两栖机器人推进机构设计与水动力学分析

根据两栖机器人对水陆两种环境的适应需求,设计了一套水陆两用的机器人推进机构。基于水动力学原理,对机器人推进机构的轮片在水下产生的推动力进行了分析。分析结果表明,两栖机器人水下推进力与轮片的弧度,截面面积及转动速度等因素有关。根据分析结果对推进机构参数进行了优化选择。     

机械胸鳍式仿生水下机器人的动力学特性研究

对新近研制的仿生水下机器人Robo—Mackerel，建立其在胸鳍摆动模式下游动的物理模型，并给出机械胸鳍摆动的运动方程。利用库达-儒柯夫斯基定律和二维叶素理论，分析Robo—Mackerel巡游时受到的流体作用力。通过动力学仿真，计算Robo—Mackerel的游速、推进力、瞬时功率和平均效率等水下推进性能指标。为有效地提高Robo—Mackerel的水下推进性能，分析讨论了机械胸鳍摆动各运动学参数和上述指标的关系，并提出各运动学参数的最优值。     

基于联合运动规划的可变形履带机器人在线翻越楼梯控制方法

楼梯是室内环境中最典型的障碍物之一,其对执行废墟搜救任务的机器人的机动性能提出较高要求。针对机器人翻越楼梯过程中的攀爬能力和稳定性问题,提出一种基于实时状态预测的在线翻越楼梯控制方法,该方法不仅适用于常规机器人,同样适用于异构模块化可变形履带机器人。在对机器人翻越过程中的步态进行联合运动规划基础之上,利用传感器完成楼梯参数辨识,同时对机器人翻越楼梯的基本过程进行阶段划分,并进行运动学和准静态力学分析,针对翻越楼梯过程的各阶段建立模块联合运动协调准则、防止倾翻准则和防止干涉准则,实现机器人翻越楼梯运动的实时在线预测控制。基于可变形履带机器人Amoeba-II平台的翻越楼梯试验验证基于联合运动规划的在线翻越楼梯控制方法的有效性。     

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.