新型四足步行机器人的腿机构设计

结合腿部机构的典型姿态,规划了四足机器人的合理步态。依据设计参数,运用三维模型软件UG建立了四足机器人的三维实体模型,导入ADAMS中添加约束和动力,进行运动仿真。仿真试验结果表明机构运动中腿部所受冲击力过大,因此进行机构方案改进,重新设计了小腿机构。改进的机构试验表明,四足机器人的腿部受力明显得到了改善,从而机构的设计得到了优化。     

四足机器人腿部机构运动学分析与实现

通过研究犬类骨骼结构,确定了机器人关节数和腿部机构简图,提出一种四足机器人腿部机构运动学分析和实现的方法.对机器人进行运动学建模,借助模型进行了机器人正逆解计算以及求出腿部机构关节转角与电机转圈数之间的关系.借助ADAMS动力学仿真软件,验证单腿机构的运动起立过程和关键参数变化规律,逆向运动学仿真得到了关节扭矩等关键数据,设计了以滚珠丝杆为传动机构的腿部结构.实践表明,该机构的设计方法有利于仿生机器人的研究与发展.     

四足机器人腿部机构运动学分析与实现

通过研究犬类骨骼结构,确定了机器人关节数和腿部机构简图,提出一种四足机器人腿部机构运动学分析和实现的方法.对机器人进行运动学建模,借助模型进行了机器人正逆解计算以及求出腿部机构关节转角与电机转圈数之间的关系.借助ADAMS动力学仿真软件,验证单腿机构的运动起立过程和关键参数变化规律,逆向运动学仿真得到了关节扭矩等关键数据,设计了以滚珠丝杆为传动机构的腿部结构.实践表明,该机构的设计方法有利于仿生机器人的研究与发展.     

四足机器人腿部机构运动学分析与实现

通过研究犬类骨骼结构,确定了机器人关节数和腿部机构简图,提出一种四足机器人腿部机构运动学分析和实现的方法.对机器人进行运动学建模,借助模型进行了机器人正逆解计算以及求出腿部机构关节转角与电机转圈数之间的关系.借助ADAMS动力学仿真软件,验证单腿机构的运动起立过程和关键参数变化规律,逆向运动学仿真得到了关节扭矩等关键数据,设计了以滚珠丝杆为传动机构的腿部结构.实践表明,该机构的设计方法有利于仿生机器人的研究与发展.     

四足机器人单自由度腿部优化设计及仿真

基于仿生原理的四足机器人是当今国内外众多学者研究的热点。针对四足机器人运动平稳性的要求,提出了一种竖直方向改进型等速运动规律和前进方向仿生运动规律相结合的无冲击足端轨迹形式,推导出分段函数表达式;针对四足机器人存在的驱动多、腿部刚度弱的情况,构思了一种由两个曲柄摇杆机构、同步带传动和一对外啮合圆柱齿轮传动组成的单自由度的新型腿部机构,并建立该机构的运动学模型,推导了其足端的坐标;综合利用遗传算法和非线性优化一般方法,以无冲击的足端轨迹的逼近度为目标,优化计算了机构各构件的最佳运动尺寸和初始位置;使用三维建模软件搭建简化的虚拟样机模型,并导入到Adams软件中进行了Trot步态仿真试验,运动效果达到了预期设计。所提出的无冲击轨迹可以为其他足式机器人的足端轨迹规划提供参考,由两个曲柄摇杆机构组成的多连杆腿部机构优化设计方法为足式机器人腿部设计提供了基础和创新思路。     

八足机器人行走机构设计及其运动学分析

针对多足机器人在变地形环境下快速行走的问题,对多足机器人的腿部机构与运动模式进行了研究,设计了两种机器人腿部行走机构,即六连杆腿部机构与齿轮传动腿部机构,并基于这两种腿部行走机构组合了一种八足机器人。首先,对八足机器人各腿部行走机构和整体结构进行了设计分析,根据各腿部机构选择适用步态进行了研究,即前后连杆腿的对角步态与中部齿轮腿的单线直行步态;然后,研究了机器人的两种不同腿结构的行走性能,对其进行了运动学分析;最后,整体分析了机器人对角步态和越阶梯两种运动模式,并通过ADAMS软件对机器人两种运动模式进行了运动仿真,将后处理曲线与运动分析进行了对比。研究结果表明:机器人行走具有稳定性,两种运动模式具有可行性。     

电液驱动六足机器人三维空间力学分析

建立了六足机器人的腿部机构三维空间模型,对其关节液压缸设计优化问题进行了讨论。接着进一步建立了腿部机构力学模型,通过对静力学分析得到了机器人稳定状态时各关节的输出力矩特性,同时采用拉格朗日方法对机器人单腿机构进行了动力学分析,得到了单腿结构在运动过程中各关节的输出力矩特性。最后根据动力学分析结果用ADAMS软件对单腿机构进行了足端轨迹和腿部位姿仿真,仿真结果验证了腿部结构的运动平稳性,为后续研究工作提供了理论支撑。     

一种新型轮腿四足机器人腿部机构结构参数优化

目前对于躯体宽度可变、具有腰关节的轮腿四足机器人的研究相对较少,针对这一问题,提出了一种新型轮腿四足机器人,对该机器人的腿部机构结构参数尺寸进行了优化研究.采用Solidworks软件建立了四足机器人的整机模型及腿部结构模型;对机器人腿部机构进行了运动学分析,推导出了其腿部机构的位置正反解公式,并利用MATLAB对位置...     

四足侦察机器人的设计与研究

针对便携式、微型化多地形适应型侦察设备的迫切需求,从仿生的角度设计出了一款四足侦察机器人。在确定采取外肘内膝总体对称布置后,首先完成了机器人腿部、支架和外壳等机构和结构件设计;随后对其中的腿部支撑、传动减振和关节驱动函数进行了设计说明;最后在动力学仿真软件中对四足机器人腿关节运动、整机运动、足端运动进行了运动学分析和慢跑步态的动力学分析,证明该机器人在运动平稳性和速度稳定性方面能够满足侦察设备的要求。     

一种可重构四足移动机器人的几何约束及其抗倾覆能力

提出了一种在倾倒后具有自我恢复能力的四足并联移动机器人。该四足机器人的腿部结构由一种可重构空间六杆机构构成,该六杆机构由两个改进型球面五杆机构并联而成,具有两种不同的运动位形。其中,运动位形Ⅰ具有1R2T共3个自由度,满足四足机器人对腿部行走机构的自由度需求;运动位形Ⅱ具有2个自由度且工作空间很大,满足其翻身所需要的工作空间条件。运用螺旋理论对球面五杆机构和可重构六杆机构的两种运动位形进行了几何约束分析,这两种运动位形具有互锁性能。运用D-H法对可重构六杆机构进行了逆运动学分析并得到其工作空间,验证了四足机器人翻身的可实现性。分析了四足机器人在翻身时的步态,得出了其在倾倒后自我恢复时腿部电机转动角度与机器人机身重心的关系。在四足机器人的翻身过程中,其腿部的可重构六杆机构均处于运动位形Ⅱ。在Adams软件中验证了预设翻身步态的正确性与合理性。     

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.     

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.