曲面相机阵列多分辨成像方法

针对现有成像系统因数据冗余而无法兼顾大视场、高分辨、高效性的问题,结合人眼视网膜变分辨成像和并列式复眼成像原理,设计一种多分辨率成像的复合仿生成像系统.该成像系统按照球面和平面兼顾的曲面布局方式,利用11个相机镜头构建相机阵列,组成了四个等级分辨率的子眼拍摄模块.通过物距100 m的远景实验和物距10 m的近景实验发现,该系统在实现高分辨成像的同时,获得总视场达150.8°×37.8°.多分辨率成像实验结果表明,该系统获取的图像的分辨率从中心视场到边缘视场逐渐降低,并且相较于中心清晰全视场成像,四级分辨率成像的拼接图像数据量减少了17.2倍的数据冗余.     

3D-Printed Bionic Ear for Sound Identification and Localization Based on In Situ Polling of PVDF-TrFE Film

Bionic acoustic sensors are an indispensable part to realize interactions between humans and robotics. In this work, a PVDF-TrFE sensor array with multiple active pixels combined with a 3D-printed bionic ear model is prepared, which can accurately detect sounds with different frequencies and locate the sound source from different directions. The PVDF-TrFE sensor array can clearly identify the sound within 25 cm, and the error between the accepted sound frequency and the original input frequency is less than 0.001%. Through the algorithm analysis of the input signal, the location of the sound source can be immediately analyzed. Compared with other acoustic sensors, this sensor has the advantages of being self-powered, small size, and high flexibility, which holds great potential for bionic applications.     

自振荡凝胶的仿生运动

定向运动是生命体最基本的功能,是其进化、生存和繁衍的前提。近年来为了研究生命体的运动机制,许多人工系统被相继开发并用于模拟部分生命体的运动行为。在诸多人工仿生系统里,自振荡凝胶由于同时具有内部驱动产生动能、运动定向性、无缆化和环境自适应等性能而备受瞩目。本文介绍了自振荡凝胶仿生运动的化学-机械能转换的理论根源并综述了仿生运动模式研究近期的进展,在此基础上展望了自振荡凝胶运动研究面临的机遇、挑战和未来发展方向。     

仿生非光滑表面铸铁材料的常温摩擦磨损性能

模仿动物体表形态,在试样表面通过激光雕刻出有规则分布的凹坑以及条纹等非光滑单元体,研究了具有非光滑表面材料的摩擦磨损性能.结果表明:非光滑表面材料的耐磨性较光滑表面提高1倍以上,摩擦系数提高66%以上;当非光滑表面的单元体硬度越高、直径越大和间距越小时,其耐磨性能越好,摩擦系数越大.这是由于激光加工的单元体相当于在母体上增加了许多强化质点,比母体具有较高的硬度和致密性,能够提高抗磨性,增加表面粗糙度,所以其耐磨性提高,摩擦系数增大.     

Cascaded quasi-zero stiffness nonlinear low-frequency vibration isolator inspired by human spine

Human motion induced vibration has very low frequency, ranging from 2 Hz to 5 Hz. Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the high load capacity. In this paper, inspired by the human spine, we propose a novel bionic human spine inspired quasi-zero stiffness (QZS) vibration isolator which consists of a cascaded multi-stage negative stiffness structure. The force and stiffness characteristics are investigated first, the dynamic model is established by Newton’s second law, and the isolation performance is analyzed by the harmonic balance method (HBM). Numerical results show that the bionic isolator can obtain better low-frequency isolation performance by increasing the number of negative structure stages, and reducing the damping values and external force values can obtain better low-frequency isolation performance. In comparison with the linear structure and existing traditional QZS isolator, the bionic spine isolator has better vibration isolation performance in low-frequency regions. It paves the way for the design of bionic ultra-low-frequency isolators and shows potential in many engineering applications.

     

基于差分Pattern时延差编码和海豚whistles信号的仿生水声通信技术研究

为解决传统的隐蔽水声通信方法带来的通信性能降低问题, 提出了一种将差分 Pattern 时延差编码通信体制与海豚whistles信号相结合的仿生水声通信技术. 海豚whistles信号频带较窄且各信息码元间隔不等、码元之间互相关性较弱, 选取whistles信号作同步码和Pattern 码, 并以相邻whistles信号之间的时延差值携带信息. 这种仿生的水声通信信号不易被敌方探测、截获, 且差分Pattern时延差特殊的编码方式也不易使信息被破译, 因此该水声通信技术具有较强的隐蔽性和保密性, 且在抗码间干扰以及抗多普勒效应方面具有优异性能. 本文对系统进行了水池实验, 在信噪比为0 dB、存在相对运动时实现了通信速率为67 bit/s的低误码数据传输, 验证了系统的有效性、稳健性和隐蔽性. 关键词： 仿生水声通信 差分Pattern时延差编码 海豚whistles信号 隐蔽性     

拓扑优化与仿生设计在空间太阳能电站热设计中的应用

高效热设计与热控制是高功率连续微波无线传能与空间太阳电站(SSPS)领域的研究热点之一,引起了国内外同行专家的高度关注与浓厚兴趣.本文针对欧米伽空间太阳能电站(SSPS-OM EGA)的结构特点及其对热设计与热控提出的巨大挑战,基于拓扑优化与仿生的思想,提出了一种新的热设计策略与方法.首先,联合流体出口边界与流道构型,建立最小化表面平均温度和流道压力损失的优化模型,得到陀螺馈源光伏阵上背板流道最优的出口位置与最佳拓扑构型,使馈源中的热量导出效率明显提高.其次,建立了仿蝴蝶翅膀形状与结构的对自由空间辐射散热的布局与拓扑优化模型,在满足性态前提下显著提升辐射效率.再者,分析推导了非线性目标和约束函数关于设计变量的灵敏度计算公式与迭代格式.最后,将本文模型与方法应用于欧米伽空间太阳能电站热设计,得到了满意的结果.     

基于仿生设计的风力发电机叶片力学性能的实验研究

根据风力机的基本理论和相似理论设计了一个翼型为SG6050,半径为1m的小型风力机叶片。运用结构仿生学原理,对所设计的风力机叶片进行了仿生物中轴铺层设计。通过模态实验与应变实验,比较了传统设计与仿生设计两种不同风力机叶片的力学性能。模态实验结果表明,基于仿生设计的叶片的前六阶固有频率比传统叶片的前六阶固有频率减少约8％;两种叶片的固有频率均满足设计要求;仿生设计的叶片几乎不会改变叶片的动态特性。而应变实验表明,仿生设计的叶片在各种工况下的应变均大于传统的叶片约10％～20％。新设计的叶片具有较好的柔性,有效减小了叶片的应力,提高了叶片的疲劳寿命。     

带沟槽结构的平板流动中的熵产分析

基于大涡模拟，采用Fluent软件对带沟槽结构的平板流动过程进行熵产分析，探究沟槽结构引起的熵产变化规律.结果表明：沟槽结构能减少流动过程中的熵产，在30 m·s^-1时（Re≈20 000），近壁区总熵产减少约25%，40 m·s^-1时（Re≈27 000）减少约19%，但其结构对后续流动没有持续性影响，且随着法向高度的增加，影响逐渐变小；熵产在沟槽顶端部分的数值远大于其他区域，湍流作用引起的熵产起主要作用.所得结论为优化沟槽结构减阻提供了理论依据.     

Fast Screening of Biomembrane-Permeable Compounds in Herbal Medicines Using Bubble-Generating Magnetic Liposomes Coupled with LC–MS

A novel strategy based on the use of bionic membrane camouflaged magnetic particles and LC–MS was developed to quickly screen the biomembrane-permeable compounds in herbal medicines. The bionic membrane was constructed by bubble-generating magnetic liposomes loaded with NH₄HCO₃ (BMLs). The lipid bilayer structure of the liposomes enabled BMLs to capture biomembrane-permeable compounds from a herbal extract. The BMLs carrying the compounds were then separated from the extract by a magnetic field. Upon heat treatment, NH₄HCO₃ rapidly decomposed to form CO₂ bubbles within the liposomal bilayer, and the captured compounds were released from BMLs and analyzed by LC–MS. Jinlingzi San (JLZS), which contains various natural ingredients, was chosen to assess the feasibility of the proposed method. As a result, nine potential permeable compounds captured by BMLs were identified for the first time. Moreover, an in vivo animal study found that most of the compounds screened out by the proposed method were absorbed into the blood. The study provides a powerful tool for rapid and simultaneous prediction of multiple biomembrane-permeable components.