用于星球探测的仿生采样器研究
文献类型:学位论文
作者 | 冯靖凯; 张延安![]() |
学位类别 | 硕士 |
答辩日期 | 2018-05-17 |
授予单位 | 中国科学院沈阳自动化研究所 |
授予地点 | 沈阳 |
导师 | 刘金国 |
关键词 | 星球表面探测 采样器 树蜂产卵管 肌肉模型 柔性臂 |
其他题名 | Study on the Bionic Sampler Used for the Planetary Exploration |
学位专业 | 机械工程 |
中文摘要 | 仿生技术在航天领域有着广泛的应用,为科学难题提供了新思路和新方法。树蜂产卵管是一种天然钻探,可以高效地在树干进行钻洞,切削运动表现为直线形式,而非旋转形式,其中蕴藏的生物机理对于新型钻探和取样技术的发展,具有极高的科研价值。本文基于仿生学原理,从树蜂产卵管的微观结构和宏观动态变化来进行研究,设计了一款结构紧凑、功耗低、体积小、集钻探和取样功能为一体的可伸展仿生采样器,并从钻探过程和肌肉驱动解释机理,对柔性臂和钻头结构进行仿真和分析,本论文的研究内容如下: (1)从树蜂钻洞的宏观特性角度,分析了树蜂在钻探前、钻探时和钻探毕三个过程。通过分析刺探三种不同树干环境,发现钻探前的刺探是为了选择最佳钻探位置。根据树蜂产卵管的微观生物结构和在钻探过程中的形态,发现树蜂产卵管由三个瓣膜组成,故提出三瓣式仿生采样器,并分别对伸缩仓、可伸展柔性臂和钻头部分进行设计。钻头部分的腹钻瓣和内钻瓣用于钻进,背钻瓣用于采样,根据运动学仿真,验证了运动方式的可行性。 (2)对树蜂在钻洞过程中,与产卵管三个瓣膜相连的腹节观察,分析其驱动机理,发现腹产卵瓣和内产卵瓣由第一瓣膜肌肉驱动,背产卵瓣由第二瓣膜肌肉驱动,两个肌肉组织的收缩方式不同,前者为等张收缩,后者为等长收缩。根据生物体壁肌构成,结合Hill肌肉三元素模型,提出了体壁肌的收缩元多元串并联模型。对其在激活度和肌肉长度时变模型的分析,验证了激活元元空间位置和肌肉长度对肌肉-肌腱收缩力有影响。 (3)基于薄壳理论对单层柔性臂进行面素受力分析,其理论值与有限元分析的结果一致。结合接触力学,对仿生采样器可伸展柔性臂面素受力进行理论推导,并对参数模型进行有限元分析,研究了各参数与一阶临界弯矩之间的关系,并给出估算公式。 (4)对钻头部分建立了三瓣对称式和三瓣非对称式结构,采用SPH方法分析了钻头与月壤间相互作用。将二者在钻进过程中的受力进行对比,发现与树蜂产卵管生物结构一致的三瓣非对称式结构在钻进过程中受力小于三瓣对称式结构,且应力分布优于后者。对不同驱动频率的仿真结果,结果表明较高的驱动频率可使钻头在钻进过程中受力稳定。 (5)根据仿生设计,研制了原理样机,并搭建实验平台和测控系统,分别对钻头钻探时,柔性臂的弯矩和钻头受力进行测量。针对不同的实验对象进行钻探和取样,验证了方案的可行性。 |
英文摘要 | Bionic technology has wide applications in the aerospace realm, providing new ideas and methods for scientific problems. Wood wasp ovipositor is a natural drilling, which can efficiently drill holes in the tree trunk. The cutting movement is not rotary but linear motion, and the covered biological mechanism is extremely valuable for the development of new drilling and sampling techniques. Based on the principle of bionics, this paper studies the microscopic structure and macroscopic dynamic changes of wood wasp ovipositor, and designs a stretchable bionic sampler with compact structure, low power consumption, small volume, integrating drilling and sampling functions. And from the drilling process and the muscle-driven to explain the mechanism, simulate and analyze the structure of flexible arm and drill bit. The content of this paper is as follows: (1) From the perspective of the macroscopic characteristics when wood wasp drills hole, three processes are analyzed, including pre-drilling, drilling and post-drilling. By analyzing three different trunk conditions, it can be concluded that the pre-drilling overture is to select the best drilling position. According to the micro biological structure of wood wasp ovipositor and the shape during the drilling process, it is found that the ovipositor is composed of three valves, so a three-valves bionic sampler is proposed. And the retractable cabin, the flexible arm and the drill bit are respectively designed. The ventral valve and the middle valve are used for drilling, and the dorsal valve is used for sampling. According to the kinematics simulation, the feasibility of the movement is verified. (2) By observing the abdominal segment connected to the three valves of the ovipositor during the process of drilling hole, and the driving mechanism is analyzed. It is found that the ventral valve and the middle valve are driven by the first valve muscle, and the dorsal valve is driven by the second valve muscle. However, the forms of these two muscle tissue contraction are different: the former is isotonic contraction and the latter is isometric contraction. According to the composition of skeletal muscle and combination with Hill three-element muscle model, multi-elements series-parallel model of the contraction element is proposed. By analyzing the time-varying model of muscle activation and length, it is confirmed that the spatial location of the activation element and muscle length have an effect on muscle-tendon contraction force. (3) Based on the shell theory, force of the monolayer flexible arm differential element is analyzed, the theoretical value is consistent with the result of finite element analysis. Combining contact mechanics, the force of the bionic sampler's extensible flexible arm element is performed. By performing finite element analysis on the parametric model and the relationship between each parameter and the first-order critical bending moment, the estimation formula is given. (4) The three-valves symmetric and three-valves asymmetric structures are established for the drill bit. The SPH method is used to analyze the interaction between the drill bit and lunar soil. Comparing the force of two structures in the drilling process, it is found that the three-valves asymmetrical structure that is consistent with the biological structure of wood wasp ovipositor is less than the three-valves symmetrical structure, and the stress distribution is better than the latter. Simulation results for different drive frequencies show that the higher drive frequency makes the drill stable during drilling. (5) According to the bionic design, a prototype is developed, experimental platform and control system are set up to measure the bending moment of the flexible arm and the force of the drill bit during drilling. Drilling and sampling are carried out for different experimental subjects to verify the feasibility of the scheme. |
语种 | 中文 |
产权排序 | 1 |
页码 | 104页 |
源URL | [http://ir.sia.cn/handle/173321/21767] ![]() |
专题 | 沈阳自动化研究所_其他 |
推荐引用方式 GB/T 7714 | 冯靖凯,张延安. 用于星球探测的仿生采样器研究[D]. 沈阳. 中国科学院沈阳自动化研究所. 2018. |
入库方式: OAI收割
来源:沈阳自动化研究所
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