两自由度仿生扑翼飞行机器人设计与运动分析

根据鸟类的飞行特性,设计了一种两自由度仿生扑翼飞行机器人。扑翼飞行机器人采用单电机驱动,能够实现扑动、扭转两自由度耦合运动,结构紧凑、运动高效,且机翼的运动形式接近鸟类。首先根据总体设计目标提出扑动-扭转耦合机构的运动特性要求,基于Adams建立了扑动-扭转耦合扑翼机构的运动学模型,通过仿真分析得到扑动和扭转运动的变化规律,并得到了翼尖轨迹曲线。扑动-扭转耦合机构的参数与设计结果达到了扑翼机构的运动要求,为仿生扑翼飞行机器人的设计和研究奠定了基础。     

仿鹰扑翼飞行器设计及多飞行模式的实现

现有仿生扑翼飞行器大多针对单一飞行模式进行设计与研究,无法实现复杂多变的飞行姿态。文中根据鹰的飞行特性,以空间RSSR机构和多连杆机构为出发点,设计了一种扑动-折叠-扭转的仿鹰扑翼机构,以实现多飞行模式。首先,通过鹰的仿生学研究,根据总体设计目标提出多飞行模式扑翼飞行器功能设计要求;其次,基于XFLR5建立了多飞行模式扑翼的气动力模型,分析了起飞、巡航、降落3种典型飞行模式下的翅翼气动力的变化规律;最后,根据飞行参数建立了机构的运动学模型,通过仿真分析得到扑翼在不同飞行模式下的运动变化规律及翼尖轨迹曲线。证明该扑翼机构具有良好的仿生运动特性和气动特性,为多飞行模式微型扑翼飞行器提供了设计参考。     

一种柔性微型扑翼设计及其气动力特性的试验研究

微型扑翼机以其优良的机动性、低噪音、低成本、执行任务的多功能性以及在现代高科技局部战争中的潜在应用价值而得到各科技先进国家的重视,投入了大量精力开展研究工作。在我国也已经初步开展对微型扑翼机研究。但由于与微型扑翼飞行相关的低雷诺数空气动力学研究还处于萌芽阶段,对微型扑翼的设计研究工作尚无可供指导的成熟理论和借鉴的经验,目前微型扑翼的设计研究基本上是以试验为主。本文参照动物的扑翼飞行实例和固定翼飞行器机翼设计的经验,在对扑翼飞行基本原理分析研究的基础上,设计制作了一种微型扑翼及扑翼的驱动机构,采用直流电动机作为动力,通过调节驱动电压来控制扑动的频率。并对该微型扑翼进行了空气动力特性试验,得到了微型扑翼的空气动力特性,并从中得出了影响扑动升力的一些因素。实验结果表明,具有柔性翼面的扑翼,其产生的升力和推力较高而且比较稳定。     

仿生扑翼结构优化设计及动力学仿真分析

针对目前飞行器结构复杂、效率低下及动作单一等问题,设计一种新型仿生扑翼飞行机构,仅通过单驱动装置即可实现机构扑翼的扑动、折叠、扭转等运动。依据生物尺度率设计扑翼机构的结构尺寸并对机构参数进行优化;通过SolidWorks构建仿生三维模型并基于ANSYS Workbench对扑翼机构进行有限元分析,得到扑翼齿轮组、曲柄、主翼杆等主要部件的总形变、应力、等效应变及主、副翼动力学运动参数,为仿生样机研制提供理论支持。     

仿生扑翼飞行器翅翼驱动方式的研究现状及展望

随着仿生扑翼飞行器的微型化，当扑翼飞行器达到昆虫置级的时候，任何复杂的运动系统都将面临难以实现的问题，翅翼的驱动方式也将面临新的挑战。本文从仿生飞行的历史与现状出发，论述了国内、外各类仿生扑翼飞行器翅翼驱动方式的研究状况。基于将昆翅视为柔性翅的观点，提出了仿生扑翼飞行器未来的研究前景翅翼在自适应变形状态下施以简单的节律运动将是仿生扑翼飞行器翅翼驱动方式的发展趋势之一。     

扑翼飞行器驱动机构的优化设计与仿真

针对目前双曲柄双摇杆结构应用在扑翼飞行器设计上较少,研究分析了扑翼驱动机构基于最小传动角最大的优化设计方法。在对传统四杆机构图解法的基础上,建立最小传动角与扑翼机架长度的关系模型。根据鸟类扑翼飞行的仿生条件,导出了机架安装角与扑翼扑动幅值、曲柄驱动角运动方程。利用MATLAB进行求解,确定驱动机构最优设计方案。建立扑翼驱动机构的虚拟样机,在ADAMS平台上进行虚拟运动仿真。结果表明,驱动机构的优化设计模型与扑翼扑动理论参数模型一致,此优化设计方法可行实用。     

仿生扑翼飞行简化力学模型及其实验研究

在研究鸟飞行机制的基础上，通过对扑翼飞行翅的简化和分析，建立了仿生扑翼飞行的简化力学模型，结合翼形导出了在一个扑动周期中翅上所产生的平均前进力和升力公式。实验证明了该简化力学模型及相应力学分析的可靠性和正确性。研究成果为进一步研制仿生扑翼飞行器提供了理论依据。     

微扑翼飞行器总体设计及实验

提出了适合工程实际的微扑翼飞行器的设计方法.利用几何相似原理,拟合了以翼展为基本参数的仿生公式,并确定了飞行参数、结构参数和动力参数.根据初步的仿生设计结果,进行传动结构、翅翼尾翼等总体结构设计,并按照运动学分析、气动力分析、动力学分析相结合的动态分析方法研究了扑翼样机理论上产生的升力.与风洞实验结果比较表明,平均升力误差为0.61 g,基本满足设计要求,为微扑翼飞行器的研制提供了理论和实验依据.     

可变幅扑翼飞行器设计及多飞行模式实现

针对目前扑翼飞行器飞行模式单一,无法灵活调整飞行姿态的问题,设计了一款可变幅扑翼飞行器,通过调节翅翼扑动幅值,实现扑翼运动姿态和飞行模式切换.建立可变幅扑翼飞行器机构运动学模型,基于Adams和Matlab进行联合仿真,对扑翼飞行器进行运动特性分析.建立多飞行模式下的气动模型,通过XFLR5软件分析可变幅扑翼飞行器的气动特性,通过设定相关参数,实现了起飞、快速飞行、慢速巡航等多种飞行模式,提高了扑翼飞行器的灵活性,为未来扑翼飞行器的进一步发展提供了研究基础.     

基于虚拟仪器的微型扑翼风洞实验系统研究

为了解决微型扑翼气动特性实验所面临的控制和测量参数多、气动力/力矩量值小、实时性强、耦合性高的困难,研制了基于虚拟仪器(Ⅵ)的微型扑翼飞行器风洞实验系统.该系统以西北某大学现有微型风洞为基础,采用高精度六分力天平、角度传感器、新型机翼扑动机构、可编程电源及工控机等设备,利用基于虚拟仪器(Ⅵ)的LabView软件对上述硬件设备进行集中控制及数据处理,可准确获得随时间变化的扑翼气动力,力矩、扑动角度,角速度、扑动输入,输出功率等数据.     

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...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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.