复合式驱动小型两栖机器人水下运动控制研究

针对两栖环境中机器人多自由度灵活稳定运动的需求,设计了一种具有"轮-腿-矢量喷水"复合驱动机制的小型两栖球形机器人。首先介绍了机器人的主要结构组成:一个密闭的上半球壳、两个可开关的1/4球壳、4条复合式驱动腿以及滑行模块等;其次,对球形机器人的复合驱动机制进行分析和建模;接着,根据水下环境和机器人的特性,设计了基于传统PID算法的神经网络自整定控制算法;最后,在室内水池中进行了机器人运动的实验测试。实验结果表明,机器人在水中运动性能良好,运动轨迹和姿态角误差在控制器接受范围之内。所提出的具有复合驱动机制的自主式两栖球形机器人,在滨海两栖环境的资源勘测等方面具有广阔的应用前景。     

小型两栖球形机器人陆地运动建模及实验分析

为实现两栖环境和狭窄空间内生物搜救及跟踪调查等任务,需要机器人具备高灵活性、微型结构和多功能运动模式等特点。智能驱动器驱动的仿生微型机器人及电机驱动的中小型机器人很难同时满足要求。因此,提出由一个仿生小型两栖球形母机器人和若干微型子机器人组成的子母机器人系统,母机器人由电机驱动,具有矢量喷水-四足步行复合式一体化驱动机制、水陆两栖运动模式等特点,子机器人由智能驱动器驱动。首先对子母机器人系统进行了描述;其次对两栖母机器人进行了运动学建模分析、陆地运动步态设计;最后搭建了两栖球形母机器人原型机样机,且基于所设计的静态爬行/动态对角小跑步态进行了一系列的陆地运动实验,验证了母机器人陆上静/动态步态运动的灵活性和可行性。     

球—轮复合可变形机器人的结构设计与分析

设计一种将球形机器人与轮式机器人运动特点相结合的可变形移动机器人。该移动机器人可以适应多种复杂的地形环境,自身几何形状发生变化以实现球形和轮式机器人互换。球—轮复合型移动机器人的机构系统由可变形球壳、球体推进装置和轮式驱动装置组成。通过对可变形球壳的拉伸和收缩实现球形和轮式机器人之间的角色交换。运用理论推导和参数优化等方法对球—轮复合型移动机器人中的变形球壳、车轮、和驱动重摆的结构尺寸进行分析,并通过仿真试验验证了机构尺寸参数选择的合理性,为该复合型移动机器人的机构设计提供了理论依据。最后通过实物试验验证,证实了该移动机器人实现的可行性。     

十二自由度四足机器人的腿机构设计与步行实验

针对四足机器人研究中存在电机驱动不强和效率低的问题,采用耦合驱动的腿机构来构建四足机器人。设计了具有复合运动模式的耦合驱动髋关节,通过髋关节两个电机选取不同的旋转方向和速度,产生多角度的复合运动。运用此腿机构研制具有12个主动自由度的原型样机。根据静态稳定裕度,设计了机器人静态行走步态,运用分布式CAN总线搭建机器人的运动控制系统。实验证明:四足机器人运动平稳,一个运动周期移动距离为32 cm,单足抬起高度为4 cm,满足设计的要求。     

小型球形水底观测机器人设计分析与实现

面向水底信息获取和环境观测需求,基于球状壳体抵抗水压能力强,转动水阻力小,便于姿态控制特点,提出球形水底观测机器人构型,由螺旋桨推进、姿态调节和复合滚动装置组成欠驱动六自由度水下移动平台,球壳作为密闭舱保护内部电子器件,结合重摆以滚动形式实现水底滚动。通过对机器人流体力学仿真计算出水动力系数并建立水下动力学方程,进一步对机器人的螺旋桨推进、飞轮转向和球壳滚动进行分析,得出球壳优化尺寸以及飞轮匹配惯量和球壳滚动特性。基于球形机器人水下移动平台和地面监控软件的水底观测系统架构,研制出球形水底观测机器人原理样机,结合机器人的构型和运动特点制定出降落、滚动和调姿三段式水底运动观测策略,水池试验表明设计的球形水底观测机器人水中推进速度可达到1.4m/s,水底移动速度可达到0.5m/s,姿态调节速度可达到30°/s,能够实现水底图像采集,辅助岸上科研人员执行水底观测任务。     

仿鳄鱼水陆两栖机器人机构优化设计与试验验证

在分析国内外两栖仿生机器人研究最新进展的基础上,以鳄鱼为生物原型,设计一套两栖机器人爬行与游动复合机构。在对复合仿鳄鱼机构进行的仿真优化过程中,得出使得机器人运动效果最优的一组身长与腿长的比例为17:13。认为在腰部扭转的角度一定时,机器人的运动性能随着腿长与身长比例的增加而渐优;而在腰部转到极限扭转角的情况下,机器人运动性能随着腿长与身长的比例增加呈现近似抛物线规律。设计制作仿鳄鱼两栖机器人的原理样机,并进行爬行与游动试验。试验结果表明,使得机器人运动效果最佳的运动频率是2Hz。     

一种带有可伸缩臂的球形机器人建模及分析

带有可伸缩臂的球形机器人不仅能实现全方位行走,又具有对外界环境的操作能力,是一个新颖的课题。对球形机器人力学建模是运动状态分析和控制系统设计的基础。笔者针对一种新颖的带有可伸缩臂的球形机器人结构,采用Kane方法,考虑非完整约束条件建立了该系统的动力学模型。对球直线行走与S曲线行走时各关节力/力矩以及球壳欧拉角进行了仿真分析,分析结果表明合理规划球的行走轨迹,将极大地削弱球壳运动对两侧球冠与臂杆的各关节力/力矩扰动。     

球形机器人动力学建模及运动特性分析

利用凯恩方法建立了非理想条件下球形机器人的动力学模型。分析了关节摩擦、滚动摩阻力矩、球壳不圆对球形机器人运动特性的影响,给出了球形机器人运动过程中球壳打滑问题产生的原因,仿真结果为球形机器人控制策略和机械设计提供了理论依据。     

水陆两栖蛇形机器人的研制及其陆地和水下步态

针对沼泽、浅滩等复杂环境对蛇形机器人的环境适应需求,在广泛分析国内外水陆两栖蛇形机器人研究最新进展的基础上,研发一种新型水陆两栖蛇形机器人。该机器人由9个具有密封设计的万向运动单元组成,保证了样机在陆地和水中均能灵活运动。基于简化的蛇形曲线得到水陆两栖蛇形机器人的基本二维运动步态即蜿蜒运动。对两个垂直平面上,即水平面和竖直面上基本步态进行复合,由基于启发式思想的三维步态生成方法,得到包括侧向蜿蜒等运动的水陆两栖蛇形机器人的多种陆地步态和水下步态,其中S形翻滚运动和螺旋翻滚运动为蛇形机器人的两种新型步态。通过步态试验验证了水陆两栖蛇形机器人的陆地和水下运动能力。在试验过程中,对陆地和水下步态的性能做出分析,分析结果对水陆两栖蛇形机器人在陆地和水下运动的位置和姿态控制具有重要意义。     

新型轮腿机器人步态规划策略

设计了一种新型步态可切换轮腿机器人。该机器人步态切换机理易于实现且不存在冗余机构,驱动系统置于封闭空间内,可在两栖环境下应用。基于模型控制步态的策略,规划了轮腿机器人的足端轨迹;利用运动学模型分析求解出各关节变量,对步态控制策略进行研究,并利用实验样机验证了基于足端轨迹规划的机器人步态控制策略的可行性。     

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.     

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....     

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。     

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.