肩离断多自由度机器人型假肢肩部气动平衡机构的优化设计

肩离断多自由度机器人型假肢拥有6个自由度,其肩部前后摆采用旋转电机驱动,外摆采用直线电机驱动。为避免空间干涉以及减小驱动力矩,采用了一种气动支撑杆来实现对大臂关节重力矩的平衡。设计了气动支撑杆平衡结构形式,确定了结构设计中的待优化变量,建立起结构的运动数学模型,构造了结构设计的约束与目标函数。用有约束问题的最优化算法求得本结构的综合最优解,最后输出了优化设计计算结果及其运动仿真图形。     

康复用多自由度假肢大臂外摆机构的优化设计

康复用6自由度机器人型假肢的大臂外摆机构采用直线电机驱动。为得到其合理的安装结构形式,在充分考虑安装空间,传动效率以及假肢大臂的重量和运动范围等多方面因素前提下,采用了优化设计方法。建立起结构的运动数学模型,确定了设计变量,设计约束以及其目标函数,然后编制了MATLAB优化程序,采用最优化理论中的复合型算法求得本结构的综合最优解。最后根据优化结果编制了仿真程序,输出了运动仿真图形,证明了设计的合理性。     

智能假肢膝关节的优化设计及运动学分析

智能假肢膝关节是一种代偿下肢缺失功能的机械电子装置,可以采用双摇杆机构实现对假肢膝关节运动特性的模拟。针对假肢膝关节行走过程中能量消耗过大、稳定性较差的问题,以假肢膝关节机构峰值驱动力矩最小为优化目标,建立了优化模型;在满足性能与结构的约束条件下,运用复合形法对该模型进行优化求解,得到了假肢膝关节机构的最佳结构参数;在此基础上,利用ADAMS软件进行了虚拟运动仿真。结果表明:优化后的智能假肢膝关节具有优良的仿生性能,其峰值驱动力矩相比优化前降低了40%,驱动力矩变化范围缩小36%,大大地提升了智能假肢膝关节的稳定性与续航能力。     

外骨骼上肢康复机器人的结构设计与仿真研究

针对上肢轻度瘫痪患者自主进行康复理疗训练的问题,在深入了解传统康复训练的弊端和康复机器人所应具备性能的基础上,提出了一种可穿戴式的外骨骼上肢康复机器人设计方案。首先,从仿生学角度出发,对该康复机器人的整体机械结构进行了建模,并设计了3处长度调节固定机构;然后,对机器人各关节驱动力矩进行了理论分析与计算,通过模型动作编写了step函数,将函数与三维模型图导入Adams进行了动力学仿真;得到了各关节的驱动力矩曲线图,再将其与理论计算结果作了对比分析;最后,对肩关节支撑板和大臂支撑板进行了强度分析。研究结果表明:该外骨骼上肢康复机器人结构设计方案具有较高可行性,能帮助患者实现康复训练。     

基于AVR平台的六自由度仿人机械手臂控制算法研究

传统机械手臂各关节常用电机来驱动,其驱动系统较为复杂,设计难度较大。提出以AVR为控制平台,以舵机作为机械臂各关节驱动,并着重介绍了基于舵机特有的工作方式而提出的一种可以对该机械臂各关节运动速度、方向和运动量进行控制的算法。该算法同时还具备可扩展性等优点,即可以对由舵机驱动的更多自由度的机械手臂进行实时控制。     

管道清灰机器人操作臂优化设计模型的建立

为使管道清灰机器人操作臂机构的优化设计过程简化,经分析管道清灰机器人操作臂的特点,将其分解为六连杆转斗机构和举升机构两大功能相对独立的子机构。通过选取对操作臂性能影响最大的初始铲取位置时的传动比的倒数为目标函数,以边界约束、性能约束、运动协调性约束、油缸稳定性约束等为条件,建立了管道清灰机器人操作臂优化设计数学模型。应用Matlab/Simulink软件编制了优化计算程序,分析得到了管道清灰机器人操作臂的优化尺寸参数。为管道清灰机器人的整体优化提供了思路,同时,为今后此类六杆机构的设计提供一定的理论依据和方法。     

一种主动型踝关节假肢设计及动力学分析

设计了一种平衡可控变刚度主动型踝关节假肢,通过调节弹簧的预紧力,实现不同行走模式下的变刚度运动。首先采用Motion Analysis步态分析系统进行人体行走步态实验的研究,获得踝关节行走过程中的关节角度及关节力矩,为踝关节假肢设计提供理论依据;其后,进行踝关节假肢机构方案分析,利用电动机带动曲柄摇杆机构,并组合弹簧进行踝关节假肢的机构设计;最后,采用ADAMS软件进行踝关节假肢虚拟样机仿真,研究不同刚度系数对踝关节假肢运动输出的影响,仿真结果表明踝关节假肢有较好的动力输出效果,并通过实验验证了机构设计的合理性。     

基于遗传算法的6R串联机器人臂长优化设计

为了更好地优化机械臂的结构参数,提高机器人的经济实用性,设计了一款6R串联机器人,在保证机器人各关节驱动力矩不变的情况下,对机械臂的臂长进行了重新分配。以机械臂的结构长度系数最小为优化目标函数,基于MATLAB遗传算法工具箱对机械臂的臂长进行了优化设计,优化后的机械臂结构长度系数降低0.15,质量减轻0.33 kg。     

三关节连杆欠驱动手爪参数优化

欠驱动手爪抓取的性能主要由其机构设计所决定的,然而各关节的几何尺寸参数和作用在关节上的力矩对包络抓取的稳定影响是未知的,面向多自由度欠驱动机构的包络抓取稳定性研究仍存在诸多难题。提出了一种以接触力相等为目标函数的方法,以传动角和传动比为约束条件,确定欠驱动连杆关节几何参数,设计连杆欠驱动机构。并建立其优化设计模型,利用目标优化函数求解了在约束条件下的最优解。为进一步优化关节尺寸几何参数和驱动参数以及结构设计提供了一种有效的方法。     

一种上肢康复机器人重力支撑装置的设计与试验研究

在上肢康复机器人的设计中,由于患者悬臂及机器人臂自身重力的影响需要较大驱动力矩的驱动电机,且电机驱动力矩波动较大。为了防止在康复训练过程中驱动力力矩过大对患者造成的肌肉拉伤、脱臼等二次伤害,提出了一种运用气弹簧和拉簧相结合来部分抵消机器人及患者上肢重力的重力支撑装置。设计了支撑装置的运动机构。通过分析表明该装置可以有效地减小电机驱动力矩。最后,运用Pro/E对重力支撑装置进行了实体建模,导入ADAMS/View中做动力学仿真,得到了有支撑装置和无支撑装置情况下机器人主要关节驱动力矩的变化曲线;结合试验获得的驱动力矩的变化曲线,验证了该装置的应用使机器人驱动力矩的极值减小了50%以上。     

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.