基于动作捕捉技术对仿人机器人运动学分析与步态仿真

以人类的构造为原型,基于仿生学的角度,设计了一种下肢单腿7自由度的仿人机器人.通过三维光学动作捕捉系统采集人体正常行走时的运动位置坐标,分析数据,获取人体步态行走时的关节角度及下肢各关节力矩变化规律;建立了下肢7自由度运动学模型并进行逆运动学分析,求解出下肢各关节角度的变化情况,并根据步态规划求解出仿人机器人步行运动过程中下肢各关节转动角度;在UG环境中建立下肢7自由度的仿人机器人三维模型,并利用多体动力学软件Adams进行动力学仿真,结合步态运动规划求解出的角度变化情况对仿真参数进行设置,通过虚拟样机完成仿人机器人的步态行走,并将仿真数据和动作捕捉实验获取的数据结果进行对比.研究结果显示,仿人机器人能够实现稳定的步态行走,确认了整体建模思路、运动学分析以及动力学仿真的准确性.以实验结果为基准,仿真所获得的髋关节和膝关节力矩值相对于实验值的相对误差分别为6.7％和9.6％,均在合理的范围内,为仿人机器人结构设计和电机选型提供了依据.     

仿人机器人SJTU-HR1及其运动分析

SJTU-HR1是由并联关节的组成的34个自由度新型仿人形机器人,根据人体生理结构设计了其各个关节。把各个并联机构关节作为一个模块,定义了关节的输出角度和输入角度,建立仿人形机器人整体坐标系,建立手臂和腿末端的位置正反解模型。为仿人机器人运动规划,动作设计以及控制系统建立奠定基础。     

基于Simulink的仿人机器人步行运动仿真模型

在对仿人机器人完整步行运动分析的基础上,基于Simulink建立了仿人机器人步行运动仿真模型.首先,给出了仿真模型的整体结构框架;接着,建立了仿人机器人13质量块动力学模型,分析和讨论了仿人机器人行走过程中脚与地面的作用过程,基于关节驱动力矩二次型积分最小,规划得到了一组稳定的行走步态,并基于传感反射控制实现了仿人机器人复杂环境下的应用;最后,对仿真结果进行了分析和讨论.     

仿人机器人抬起重物的运动学仿真

以仿人机器人运动学为基础,运用Danevit-Hartebeng方法,建立了仿人机器人的运动坐标系。将仿人机器人抬起重物的运动分解为下肢运动和上肢运动。基于人体抬起重物的实际动作姿态,运用MATLAB Robotics Toolbox建立仿人机器人的运动学仿真模型,并对机器人各关节角度进行轨迹规划。最后建立仿人机器人的三维模型,并运用虚拟样机软件ADAMS对轨迹规划结果进行仿真。结果表明,对仿人机器人搬运重物的运动轨迹规划是可行的和精确的,为仿人机器人搬运重物的后续研究提供了参考。     

基于人体动作姿态识别的机器人仿人运动*

以关节式机器人为对象,进行机器人仿人运动研究。从人体动作姿态识别、人-机动作映射、机器人运动控制等方面,详细阐述机器人仿人运动算法。提出人体动作姿态识别方法,利用Kinect传感器捕获人体运作的关节点位置信息,在建立人体基准坐标系的基础上,为了得到描述肩、肘运动的动作信息,计算人体手臂动作的关节角度,实现人体动作姿态的识别。在分析人体肩、肘等关节和机器人机构差异性的基础上,建立人体手臂与四自由度机械手臂的人-机动作映射规则。针对机器人自由度较少,无法完全复现人体运动的情形,分析、比较不同控制策略的优缺点和适用性,寻求适合机器人操作的复现控制策略。关节式机器人接收运动控制指令,执行相应的关节运动,从而实现机器人仿人运动。相关试验验证了人体动作姿态识别和机器人仿人运动控制算法的有效性。研究成果对于提高机器人控制和操作的简单易用性、提高人机交互能力具有借鉴意义,对于扩展机器人应用领域具有实践意义。     

仿人机器人的设计与实现

根据仿人机器人实现功能的要求,对机器人各关节自由度合理安排,完成仿人机器人的机构设计。运用D-H坐标表示方法,进行坐标系选取,位姿描述和坐标变换,并建立仿人机器人的运动学方程求运动学的正逆解,从而计算了仿人机器人的运动学。由Pro/E建立实体模型导入到ADAMS中进行虚拟样机仿真,通过查看后处理器运动学仿真结果,并与计算结果相比较,从而得出结论,为物理样机的制造提供科学依据。     

气压式仿人机器人的腰部设计与运动仿真

提出了一种新型的气压式仿人机器人腰部机构,它具有结构简单和运动稳定的特点。气压式仿人机器人腰部的运动受到手部、头部和腿部等关节力矩的影响。在对机器人进行简化之后,依据高效-欧拉算法,对该仿人机器人进行整体建模,导出腰部俯仰和侧转关节的动力学模型。从动力学上分析,机器人腰部手部和腿部的运动以及外力(矩)等的影响。在Pro/e3.0上建立仿人机器人腰部结构模型,然后导入ADAMS中进行动力学仿真研究,验证了该模型的正确性。     

基于虚拟样机技术的仿人机器人电机选型

针对仿人机器人设计中电机选型的问题,提出基于虚拟样机技术的电机选型方法.在初选参考电机后,设计符合要求的机器人,使用Pro/E和ADAMS联合建立仿人机器人的虚拟样机模型,运用此虚拟样机进行机器人动力学仿真,以仿真参数为依据,进行电机系统的精确选型.最后通过比较关节负载特性曲线与电机的理想机械特性曲线,验证了电机选型的合理性.     

基于Simmechanics仿人机器人下肢的能耗分析

在对下肢动力学分析的基础上,建立符合人体运动特点的仿人机器人下肢模型,根据人体动力学方程,在机械仿真模块中建模。利用惯性动作捕捉系统和数据采集软件对人体下肢关节角度信号进行采集。基于仿真模型进行能量流动特性研究和行走能量效率计算。通过比较仿真测得的生物力学信息与计算值的吻合程度验证模型的合理性,建立能量流动方程,实现高效行走步态分析。建立的仿真模型和能量流动方程能够为设计高性能的仿人机器人提供借鉴。     

欠驱动仿袋鼠跳跃机器人动力学耦合研究

根据袋鼠的生物结构及运动特点,建立了具有欠驱动关节的仿袋鼠跳跃机器人模型。以此模型为基础,分析系统的主动关节与被动关节之间的加速度耦合效应。采用拉格朗日方方法建立了机构的动力学方程。结合实例,运用Matlab软件对机器人进行仿真分析,给出了机器人全局单关节耦合变化规律。结果表明:仿袋鼠跳跃机器人的踝关节与欠驱动关节间存在足够大的耦合并且通过动力学耦合来控制欠驱动关节的位置是可能的。动力学耦合指标对欠驱动机器人的结构设计和驱动装置位置有重要作用。     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.