基于虚拟样机技术的外骨骼助力搬运机器人结构设计与仿真研究

针对现有外骨骼助力搬运机器人结构复杂、价格昂贵的问题,对外骨骼助力搬运机器人虚拟样机技术的结构设计、运动学与控制仿真展开了研究。设计了一款结构相对简单,在人体弯腰搬运重物时对人体腰部提供助力,且肘关节设计为自锁机构的可穿戴全身外骨骼助力搬运机器人;通过对外骨骼下肢运动学模型建立了D-H坐标,进行了正逆运动学分析;利用虚拟样机技术,采用人体步态行走时所采集的实验数据,对外骨骼助力搬运机器人进行了步态运动的仿真分析与联合控制仿真。研究结果表明:所设计的外骨骼助力搬运机器人的步态仿真运动与人体的实际数据相符,验证了所设计结构的稳定性与可靠性。     

下肢外骨骼助力机器人本体结构设计与运动学分析

下肢外骨骼助力机器人是一种可以拓展人体关节机能,并可在特殊环境下作业的人机共融型机器人。基于人体下肢生物力学特点,阐述了下肢外骨骼助力机器人的机构设计原理及过程,分析了外骨骼机构的运动学关系,通过ADAMS匹配外骨骼与关节驱动范围并进行了机构优化,可以完成人体的代表性深蹲动作,为外骨骼助力行走留有较大的关节运动裕量,虚拟样机联合仿真也验证了外骨骼助力机器人的设计可行性。     

外骨骼助行机器人的人机耦合运动特性

利用Motion Analysis三维动作捕捉分析系统,实时记录人体在平地行走的运动过程,获得了步态参数,通过分组对比,研究了老年人的行走特点。根据老年人的运动特性,设计了一种老年人外骨骼助行机器人,建立了穿戴者与外骨骼助行机器人的人机耦合模型,研究了人机耦合运动特性,为外骨骼助行机器人的耦合仿生设计提供了运动学基础。     

助力下肢外骨骼直立行走过程研究

助力下肢外骨骼在行走过程的各关节角的运动学规律是研究下肢助力外骨骼的关键,其行走动作与人体行走动作有着高度的偕行性。通过光学捕捉系统结合高速摄像机获得人体不同状态下行走动作的空间坐标点,建立人体行走的棍图模型,基于MATLAB平台拟合负重为0kg、10kg、30kg行走速度为3km/h、4km/h、6km/h的关节角运动学方程,结合西南交通大学第二代助力下肢外骨骼计算膝关节处驱动液压缸的线速度及线加速度。实验结果为液压缸的选型、驱动控制系统的设计提供了理论基础。     

人机携行外骨骼双腿交替多相行走建模与仿真

为了研究人机携行外骨骼行走过程中多相交替过程下运动学参数的变化规律,基于D-H坐标系对外骨骼建立运动学模型,运用Newton-Euler递归公式计算出行走过程中的运动学表达式。为实现外骨骼与人体的携行运动,通过位移姿态传感器对人体行走过程中各关节参数进行了测量与分析。基于西南交通大学第三代人机携行外骨骼为研究对象,在Adams环境中建立虚拟样机,以人体运动参数为驱动,对外骨骼进行运动学仿真,并以双腿多相交替过程为切入点,对仿真结果进行了分析。结果可为人机携行外骨骼驱动的测控系统提供可靠依据。     

面向人体运动需求的人机闭链下肢康复外骨骼设计

患者进行康复训练时,外骨骼需满足人体康复训练需求,并保证人体各关节具有确切的运动.针对传统外骨骼髋关节自由度低及人机协调运动时产生运动偏差问题,提出一种含髋关节6连杆机构的下肢外骨骼,并对其人机接口进行优化设计,建立了人机闭链外骨骼优化模型.通过建立外骨骼单侧腿运动学模型,求解其运动学正解、反解、运动空间并检验外骨骼人机相容性,运用ADAMS软件对人体-外骨骼传统模型和优化模型进行了运动学仿真与分析.结果 表明:外骨骼末端运动空间包含人体末端运动轨迹;人体各关节运动曲线与理论期望曲线运动趋势基本相同,优化后的外骨骼明显减小人机运动偏差.研究表明,优化外骨骼有助于更精准控制下肢各关节运动,补偿人体各关节的运动偏差,证明人机闭链外骨骼设计的合理性.     

助力下肢外骨骼行走过程运动学研究

助力下肢外骨骼在行走过程的各关节角的运动学规律是研究下肢助力外骨骼的关键,其行走动作与人体行走动作有着高度的偕行性。通过光学捕捉系统结合高速摄像机获得人体不同状态下行走动作的空间坐标点,建立人体行走的棍图模型,基于MATLAB平台拟合负重为0kg、10kg、30kg、50kg行走速度为3km/h、4km/h、4.8km/h、6km/h的关节角运动学方程,结合西南交通大学第二代助力下肢外骨骼计算膝关节处驱动液压缸的线速度。实验结果为液压缸的选型、驱动控制系统的设计提供了理论基础。     

助力型外骨骼行走模式下多关节动力分配仿真分析

助力型外骨骼是一种人机高度结合的复杂机械结构。为了研究外骨骼在行走模式下负重50 kg时各关节所需驱动力矩以及功率变化规律,本文以西南交通大学第三代助力型外骨骼为研究对象,建立外骨骼模型,运用拉格朗日方程对外骨骼进行动力学分析。为实现外骨骼与人体的携行运动,通过姿态传感器对人体行走过程中关节角的变化规律进行了测量与分析,并将其作为驱动函数对ADAMS环境中的外骨骼虚拟样机进行动力学仿真,得出各关节驱动力矩变化曲线,并拟合出各关节功率曲线。所得结果增加了人机携行性以及结果的可靠性,为助力型外骨骼的驱动控制提供了参考依据。     

基于人体运动数据的下肢机器人运动学与动力学分析

针对有下肢运动障碍的患者,机器人系统与生物医学系统的结合为广大患者带来了福音,通过医学角度对人体运动数据规律的分析,可以更好地研发下肢外骨骼机器人系统。基于人体运动数据作为参考轨迹导入机器人系统的思想,通过三维红外式动作捕捉系统和三维测力平台系统实验采集人体下肢运动数据和足底力数据,利用算法对采集的数据进行滤波和拟合,通过建立下肢外骨骼机器人连杆模型,根据实验数据推导计算出髋关节和膝关节的转动角度和力矩曲线,基于Matlab设计自适应控制器验证了基于实验数据的运动学和动力学分析的有效性,为下肢外骨骼机器人电机的选型和控制系统的设计提供了数据支持和理论依据。     

外骨骼机器人体感交互控制与仿真

为使外骨骼机器人应用于康复训练时,其动作控制更便捷且符合人体运动习惯,建立了一种通过Kinect体感设备实现外骨骼机器人体感交互的运动控制方法。通过Kinect获取人体骨架关节点,构建空间向量,依据人体坐标系对上肢肩、肘关节运动角度进行分解计算,获取体感控制角度。采用卡尔曼滤波算法对角度数据进行平滑处理,改善角度数据的稳定性和实时性,并通过限速和限幅处理,确保运动的安全性。最后,将角度数据组传递到基于Lab VIEW建立的外骨骼模型,进行实时控制,根据外骨骼模型的运动效果,验证了数据计算与处理的正确性和可靠性,为建造物理样机奠定基础。     

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.