仿生长鳍波动推进系统研制的分析

综述了模仿鳐科和裸背鳗科鱼类的高机动性的波动运动方式设计仿生长鳍波动推进(long-fin undulating propulsion)系统的研究,包括长鳍波动推进系统的推进机理、长鳍波动运动的运动学和动力学研究,以及仿生长鳍波动推进实验系统的研制.在此基础上,指出了今后研究的重点--鳐科和裸背鳗科鱼类游动的运动学、动力学分析;长鳍波动推进系统的机构设计与控制方法;长鳍波动推进系统的协调控制与导航方法.     

仿生机器鱼运动方向的模糊控制研究

结合仿生机器鱼运动的三种转弯模式,设计了一种用于机器鱼运动方向控制的模糊控制器,并阐述了具体算法的实现。实验结果表明,该方法是有效的,且具有较好实时性,能够满足多仿生机器鱼协调协作研究的需要,并为未来机器鱼的实际应用奠定了良好基础。     

基于PVDF传感器的仿生机器鱼测控系统

选择离子聚合物金属复合材料(IPMC)作为驱动器,设计了一种厘米级仿生机器鱼;针对驱动器自身存在的易疲劳、易电解等缺陷及实际工程中的不确定因素给系统带来的不稳定问题,建立了基于性能稳定的聚偏二氟乙烯(PVDF)传感器的闭环测控系统,解决了开环控制存在的调节时间长、误差大的问题;提出了一种新颖的传感器并行安装方式,有效地避开了应用环境中的不利因素,实现了对驱动器状态的实时检测;在LabVIEW软件环境下进行了测控实验。实验表明,该系统能够保证仿生机器鱼长期稳定地工作。     

仿生机器鱼水球比赛控制平台视觉子系统

文章介绍了仿生机器鱼水球比赛的背景知识,分析了机器鱼软件控制平台的系统结构,详细介绍了视觉子系统的组成、功能及实现方法。实验表明,该系统能较好地满足比赛图像识别要求。     

波动鳍仿生机器鱼研究进展与分析

依靠鳍的波动实现推进的中央鳍/对鳍(Medianand/orPairedFin,MPF)模式鱼类在运动过程中身体可以不发生变形而获得推力,具有高效率,高稳定性和强机动的游动特点,对水下推进器的研发具有极大的参考价值,近年来在加强海洋资源开发力度和加快军事装备革新步伐的号召下,波动鳍仿生机器鱼受到越来越多科研人员的关注。首先对波动鳍游动鱼类进行简要介绍和分类,从机理研究和仿鱼样机两个方面对其进行综述,然后对相关的关键技术进行了分析和讨论。     

致病性鳗弧菌金属蛋白酶基因克隆及序列分析

从我国山东沿海发病的鲈鱼（Lateolabrax japonicus）分离到一株致病性鳗弧菌（Vibrio anguillarum）W-1，该菌的胞外蛋白酶活性为4226u/ml，部分纯化的胞外蛋白酶对海水养殖大菱鲆鱼有一定的毒性。应用PCR扩增，从鳗弧菌W-1染色体DNA扩增出一条长约1.925kb的特异性PCR产物，DNA序列分析表明：克隆的片段含有完整的金属蛋白酶基因阅读框，编码611个氨基酸残基的蛋白质，该金属蛋白酶基因与一株致病性鳗弧菌蛋白酶基因的核苷酸及氨基酸序列同源性为100%，而与解蛋白弧菌（V.proteolyticus)、创作弧菌（V.vulnificus）、霍乱弧菌（V.cholerae)、斑点气单胞菌（Aeromonas punctata），嗜水气单胞菌（Aeromonas hydrophila）的氨基酸序列同源性分别为73%、70%、69%、53%、51%。     

纤毛式MEMS矢量水声传感器的仿生组装

提出了一种纤毛式微机电系统（MEMS）矢量水声传感器的仿生组装技术.期望结合MEMS工艺和仿生组装工艺技术,解决复杂结构的仿生制造问题.文中简单介绍了仿生学理论以及定向探测机理.采用MEMS基硅微机械加工技术完成了传感器微结构的加工.通过模仿鱼类侧线器官神经丘感觉器的仿生结构,完成了传感器仿生微结构的组装,制作出纤毛式硅微仿生矢量水声传感器的模型样机.最后,完成了传感器的校准测试.测试结果表明,该水声传感器不但体积小、质量轻、结构简单,而且具有“8”字型的指向特性.该水声传感器的声压灵敏度为-197.7 dB（0 dB=1 V/μPa）.     

仿蟋蟀切齿叶减阻灭茬刀片设计与试验

为了降低切茬装置切割粉碎玉米根茬所需的功耗,以蟋蟀切齿叶为仿生原型设计了2种仿生灭茬刀片。应用MATLAB软件提取切齿叶部分的轮廓特征,分析其优良的减阻特性,并将此轮廓特征应用于灭茬刀片正刀刃的设计,设计出仿生刀片A;考虑到加工难易程度和经济成本,以二次函数为轮廓特征设计出仿生刀片B。在同等工作参数（前进速度为1 m/s,刀辊转速为420 r/min,耕深为50 mm）前提下,利用ANSYS/LS-DYNA软件仿真和田间试验的方法对2种仿生刀片和原型刀片的载荷状况进行对比分析。仿真结果表明：仿生刀片A和B的最大切削力（分别为881 N和908 N）较原型刀片的最大切削力（1 079 N）分别降低18.35%和15.85%;田间试验结果表明：仿生灭茬刀片A和B的平均扭矩和变异系数分别为267.894 N·m,2.31%和275.843 N·m,2.11%,原型灭茬刀片平均扭矩和变异系数为299.712 N·m和2.33%,且3种灭茬刀片的作业质量（灭茬深度和根茬粉碎率）均可达到相关国家标准。研究结果可为灭茬刀片的减阻降耗设计提供理论指导。     

仿生机器鱼水球比赛桶形失真处理

文章介绍了仿生机器鱼水球比赛的背景知识与控制系统构成,分析了桶形失真的产生原因、矫正方法、处理过程。实验表明该方法能较快地进行失真矫正,满足比赛要求。     

专家呼吁应从纳米角度加强生物分子机器研究

在香山科学会议第293次学术讨论会“纳米医药与纳米生物学前沿”上，“生物纳米机器”成为会议关注的焦点之一。专家呼吁我国应加强学科整合，从纳米角度认识生物机器，尽快在前沿基础科学研究领域中抢占一席之地。香山会议执行主席之一、科技部基础司张先恩研究员告诉记者，每个细胞都含有多种类型的分子机器。小的如各种单分子酶，能够特异性地、高效地将底物（原料）转变成细胞所需要的各种物质和能量；大的如由多种蛋白质和其它类型的分子构成的细胞器。比较复杂的蛋白质机器有核糖体蛋白质合成机器、分子马达（ATP酶）、DNA复制机器、转录机器、DNA错配修复系统、蛋白质转运机器等。美国康纳尔大学就利用ATP酶作为分子马达，加上螺旋桨式的金属镍棒，研制出了一种可以进入人体细胞的“纳米直升机”，用于清淤和载药。     

Aquatic manoeuvering with counter-propagating waves: a novel locomotive strategy

Many aquatic organisms swim by means of an undulating fin. These undulations often form a single wave travelling from one end of the fin to the other. However, when these aquatic animals are holding station or hovering, there is often a travelling wave from the head to the tail, and another moving from the tail to the head, meeting in the middle of the fin. Our study uses a biomimetic fish robot and computational fluid dynamics on a model of a real fish to uncover the mechanics of these inward counter-propagating waves. In addition, we compare the flow structure and upward force generated by inward counter-propagating waves to standing waves, unidirectional waves, and outward counter-propagating waves (i.e. one wave travelling from the middle of the fin to the head, and another wave travelling from the middle of the fin to the tail). Using digital particle image velocimetry to capture the flow structure around the fish robot, and computational fluid dynamics, we show that inward counter-propagating waves generate a clear mushroom-cloud-like flow structure with an inverted jet. The two streams of fluid set up by the two travelling waves ‘collide’ together (forming the mushroom cap) and collect into a narrow jet away from the cap (the mushroom stem). The reaction force from this jet acts to push the body in the opposite direction to the jet, perpendicular to the direction of movement provided by a single travelling wave. This downward jet provides a substantial increase in the perpendicular force when compared with the other types of fin actuation. Animals can thereby move upward if the fin is along the bottom midline of the body (or downward if on top); or left–right if the fins are along the lateral margins. In addition to illuminating how a large number of undulatory swimmers can use elongated fins to move in unexpected directions, the phenomenon of counter-propagating waves provides novel motion capabilities for systems using robotic undulators, an emerging technology for propelling underwater vehicles.     

Magnetically Propelled Fish‐Like Nanoswimmers

The swimming locomotion of fish involves a complex interplay between a deformable body and induced flow in the surrounding fluid. While innovative robotic devices, inspired by physicomechanical designs evolved in fish, have been created for underwater propulsion of large swimmers, scaling such powerful locomotion into micro‐/nanoscale propulsion remains challenging. Here, a magnetically propelled fish‐like artificial nanoswimmer is demonstrated that emulates the body and caudal fin propulsion swimming mechanism displayed by fish. To mimic the deformable fish body for periodic shape changes, template‐electrosynthesized multisegment nanowire swimmers are used to construct the artificial nanofishes (diameter 200 nm; length 4.8 μm). The resulting nanofish consists a gold segment as the head, two nickel segments as the body, and one gold segment as the caudal fin, with three flexible porous silver hinges linking each segment. Under an oscillating magnetic field, the propulsive nickel elements bend the body and caudal fin periodically to generate travelling‐wave motions with speeds exceeding 30 μm s^?1. The propulsion dynamics is studied theoretically using the immersed boundary method. Such body‐deformable nanofishes exhibit a high swimming efficiency and can serve as promising biomimetic nanorobotic devices for nanoscale biomedical applications.     

Torsional Wave Propagation in the Finitely Pre-Stretched Hollow Bi-Material Compound Circular Cylinder

This paper studies the torsional wave dispersion in the hollow bi-material compounded cylinder with finite initial strains. The investigations are carried out within the scope of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic waves in initially stressed bodies. The mechanical relations of the materials of the cylinders are described through the harmonic potential. The numerical results on the influence of the initial stretching or compression of the cylinders along the torsional wave propagation direction are presented and discussed     

粘性液体对管道中扭转导波传播特性的影响研究

对带有液体的圆柱/管中的波传播进行了研究。在流动为层流的假设下,研究了有粘性液体管道中扭转导波的位移模式和传播特性。分析了波的频散和衰减曲线,得到了粘性、密度等和第一阶扭转模态衰减的关系,确定了粘性液体对扭转导波的影响,为扭转导波在损伤检测中应用做了一些理论工作。数值计算结果与某文献中实验结果符合较好,一定程度上证明了液体中的层流假设,说明了第一阶扭转模态在损伤探测中的优势。     

管道中T(0,1)模态导波检测技术的发展与应用现状

超声导波具有检测速度快、检测范围广等优点,被广泛应用于各类缺陷的检测。而扭转模态作为超声导波的一种对称模态,具有频散小、能量集中、信号单一且易于分析的特点。综述了近年来扭转模态的发展历程,从T （0,1）扭转导波的传播与检测原理入手,对比各类激励探头的激励原理与效果,并对其进行优缺点分析。通过分析导波模态的选取原则和导波在单层管道、双层管道和充液管道中传播的性质,总结激励频率、液体粘度、液体密度等因素对扭转模态导波在管道中传播的影响,进而明确扭转模态的适用范围及适用的信号处理方法,对于今后扭转模态的发展具有借鉴意义。     

基于ADAMS的柴油机曲轴扭振仿真

以某V型8缸柴油机为研究对象,通过多体动力学方法对该曲轴进行扭振研究。首先在ADAMS中建立曲柄连杆机构的刚体模型;然后把曲轴作为柔性体,建立曲轴的有限元模型并对其进行模态计算;最后用曲轴的柔性体模型代替曲柄连杆机构的曲轴刚体模型,得到曲柄连杆机构的刚-柔混合体动力学仿真模型。对曲轴在正常工况下和单缸熄火时的扭振进行研究,得到曲轴在正常工况下和单缸熄火时的扭振特性。     

On the Some Particularities of the Torsional Wave Dispersion in a Finitely Pre-Deformed Hollow Sandwich Cylinder

This paper develops the investigations started in a work by Akbarov, Kepceler and Mert Egilmez (2011) and studies the some particularities of the torsional wave dispersion in a finitely pre-deformed sandwich hollow cylinder. The mentioned particularities relate to the influence of the stiffness ratio of the core and face layers' materials and the influence of the thickness ratio of these layers on the dispersion character of the wave under consideration. Moreover, the mentioned influences are studied for the various values of the parameter which characterizes the initial strains in the cylinder's layers. The mechanical relations of the materials of the cylinders are described through the harmonic potential. The analytical expression is presented for the low wave number limit values of the torsional wave propagation velocity. The numerical results on the foregoing influences are presented and discussed.     

柔性机械臂振动的反馈控制及数值模拟

探讨了梢端带刚体的柔性机械臂系统的动力学模型，对它存在的解耦的弯曲振动和扭转振动没计了一种形式简单的反馈控制律，用两个控制电机实现抑振和目标定位。使用Hilbert空间讨论系统特征值问题。住有限维近似模态分析基础上进行数值分析与模拟，得到系统弯曲振动、扭转振动的抑振控制效果曲线图。模拟结果与他人的试验结果比较，证实了所提出的控制律在削减振幅和快速抑振方面的有效性。     

A Remotely Controlled Transformable Soft Robot Based on Engineered Cardiac Tissue Construct

Many living organisms undergo conspicuous or abrupt changes in body structure, which is often accompanied by a behavioral change. Inspired by the natural metamorphosis, robotic systems can be designed as reconfigurable to be multifunctional. Here, a tissue‐engineered transformable robot is developed, which can be remotely controlled to assume different mechanical structures for switching locomotive function. The soft robot is actuated by a muscular tail fin that emulates the swimming of whales and works as a cellular engine powered by the synchronized contraction of striated cardiac microtissue constructs. For a transition of locomotive behavior, the robot can be optically triggered to transform from a spread to a retracted form, which effectively changes the bending stiffness of the tail fins, thus minimizing the propulsion output from the “tail fin” and effectively switching off the engine. With the unprecedented controllability and responsiveness, the transformable robot is implemented to work as a cargo carrier for programmed delivery of chemotherapeutic agents to selectively eradicate cancer cells. It is believed that the realization of the transformable concept paves a pathway for potential development of intelligent biohybrid robotic systems.     

复合式罩极电机扭转振动检测与分析

设计了一种复合式罩极电机,为双定子双转子结构,电机运行时定子绕组施加励磁,产生的旋转磁场带动转子旋转。分析了电机气隙磁场的特性,推导了电磁转矩公式,表明电机运行时存在扭转振动。研制了复合式罩极电机样机,利用传感器对电机在不同励磁状态下的转矩输出进行了检测,表明电机运行时存在扭转振动,且扭振幅值随两相励磁电压的相位差而变化,最后对变化规律进行了理论分析,结果表明:扭转振动波的相位差为两相励磁电压相位差的2倍。