【作者】 高飞；

【导师】 王振龙；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2015， 博士

【摘要】 仿生机器鱼作为鱼类游动机理和机器人技术的结合点,为研制新型的水下推进器提供了新的思路,有着重要的研究价值和应用前景。水下生物的推进方式主要可分为三类:尾鳍摆动式、胸鳍波动式和喷射推进式。目前,研制的仿生机器鱼多模拟前两类推进方式,而少有模拟喷射推进的。此外,随着智能材料的出现,将智能材料应用于仿生机器鱼的设计成为一种趋势。SMA是智能材料的一种,具有输出应力、应变大和驱动电压低的优点,适宜作为仿生机器鱼的驱动材料。本文将以SMA作为驱动材料,一方面模拟鱼类尾鳍摆动机制设计一种仿生尾鳍推进器,另一方面模拟墨鱼喷射推进机制设计一种仿墨鱼喷射推进器,并分别设计两种仿生机器鱼以验证其可行性。本文首先在借鉴鱼类尾鳍结构和动作机制的基础上研制了一种SMA驱动的仿生尾鳍,该仿生尾鳍在电流的驱动下可实现大幅度双向柔性弯曲摆动,具有仿生效果好、结构简单和动作无噪声的优点。为分析其驱动特性,在综合了其力学模型、SMA的热力学模型和本构模型等模型的基础上建立了其驱动模型。由驱动模型得出当驱动电流介于某一特定区间时,仿生尾鳍的弯曲摆角与其驱动电流之间呈近似线性关系,并得到了实验的验证,为仿生尾鳍摆角的控制提供了理论和实验基础。为进一步研究仿生尾鳍的推进性能,采用计算流体力学方法对三维仿生尾鳍的柔性弯曲摆动进行了CFD仿真和计算,仿真结果表明仿生尾鳍摆动不仅产生周期性波动的推进力,同时还产生周期性波动的侧向力,并且侧向力的波动幅值远大于推进力的波动幅值。为消除侧向力的波动,提出一种双尾鳍对称摆动的推进方式。对其进行了CFD仿真和计算,仿真结果表明双尾鳍对称摆动不仅有效抑制了侧向力的波动,而且还对推进力起到了增强作用,即双尾鳍产生的推进力大于两个独立单尾鳍产生的推进力之和。此外,对单尾鳍摆动和双尾鳍摆动时周围流体的速度场、压力场的分布特征以及流场的三维涡结构进行了分析,研究了尾鳍摆动的推进机理以及双尾鳍摆动时的流场耦合作用。随后,搭建了力学性能测试平台,分别对单尾鳍摆动和双尾鳍摆动的推进力和侧向力进行了测试,实验结果验证了仿真的正确性。本课题组在对墨鱼喷射推进机制分析的基础上,借鉴墨鱼外套膜的结构研制了一种SMA驱动的仿生外套膜结构,并藉此实现了仿生喷射推进。为进一步提高仿生外套膜的动作性能,本文对其布丝结构进行了改进,提出一种V型布丝结构仿生外套膜。为分析其动作和推进性能,在综合了其几何形变模型、力学模型、腔内压强模型以及SMA丝的热力学模型和本构模型等模型的基础上建立了其动作理论模型。利用该模型计算了仿生外套膜的动作幅值及推进力,并研究了布丝角度对动作幅值的影响,得出了最优布丝角度。随后,利用所搭建的力学性能测试平台对仿生喷射推进器的推进性能进行了测试,实验结果验证了理论模型的正确性。最后,分别研制了基于仿生尾鳍推进和基于仿生喷射推进的机器鱼,并研制了具有自主游动功能的机器鱼控制系统,为机器鱼实现自主游动提供了平台。进行了机器鱼的游动实验,实验结果表明机器鱼均可实现直线游动、转弯游动以及按预定轨迹的自主游动。此外,实验结果还表明双尾鳍推进有效的克服了单尾鳍推进时机器鱼的摇艏现象,有利于提高机器鱼游动的稳定性。更多还原

【Abstract】 As the combined point of the fish swimming mechanism and the robot technology, the bionic robot fish provides a new way to develop the new type of the underwater propeller, which has important research value and application prospect. The fish swimming modes can be divided into three types, which are caudal fin oscillatory propulsion mode, pectoral fin undulatary propulsion mode and jet propulsion mode. Currently, the majority of the bionic robot fish mimic the former two propulsion modes while fewer robot fish mimic the jet propulsion mode. Moreover, with the development of intelligent materials, the application of those materials in bionic robot fish has become to be the tendency. As a kind of the intelligent materials, SMA are the ideal actuating material for the bionic robot fish because of its greater stress and strain and lower driving voltage. In this paper, a kind of bionic caudal fin propulsor mimicing fish caudal fin propulsion and a kind of bionic jet propulsor mimicing squid jet propulsion actuated by SMA are designed respectively. Meanwhile, two kinds of bionic robot fish based above the two bionic propulor are developped to verify the feasibility.Initially, by imitating the structure and action mechanism of the caudal fin of the fish, a bionic SMA-driven caudal fin has been developed, which can achieve flexible bidirectional bending in a large range when it was driven by current. In order to analyze the driving performance of the bionic caudal fin, the driving model has been established which combined the mechanical and geometric model of the caudal fin and the thermodynamic model and the constitutive model of SMA. Through the analysis of the driving model, it can come to a conclusion that the relationship between the bending angle of the bionic caudal fin and the driving current is approximately linear when the driving current varied between a certain range. And it is verified by experiment, which provides the theoretical and experimental basis for the control of the bionic caudal fin.For further studying the propulsion performance, the CFD method was emplyed to simulate the three-dimensional flexible bending of the bionic caudal fin. The simulation results show that the flexible bending of the caudal fin can not only produce the periodic proplusive force, but also produce the periodic lateral force, and the fluctuation amplitude of the lateral force is much greater than the proplusive force.To eliminate the fluctuation of the lateral force, the twin caudal fin symmetrical swing propulsion mode was proposed. The numerical simulation was carried out and the results show that the twin caudal fin symmetrical swing mode not only effectively eliminate the fluctuation of the lateral force, but also enhance the propulsive force, which means that the propulsive force the twin caudal fin produced is greater than the sum of the propulsive force that two individual single caudal fin produced. In addition, the flow field, the pressure field and the three dimensional vorticity around the single and twin caudal fin were analyzed, and the propulsion mechanism of the caudal fin and the fluid field couple of the twin caudal fin were also analyzed. Subsequently, the propulsive force test platform was established and the propulsive force and lateral force that produce by the single caudal fin and the twin caudal fin were measured respectively. The experiment results verified the correctness of the numerical simulation.Based on the analysis of the mechanism of the cuttlefish jet propulsion, our research group developped a kind of bionic cuttlefish mantle actuated by SMA by imitating the structure of the cuttlefish mantle, through which the jet propulsion can be achieved. To further improve the action performance of the bionic mantle, we improve the arrangement of the SMA wire and put forwad a kind of bionic mantle with the V type arrangement of SMA wire. In order to anlyalze the action and propulsion performance of the V type arrangement bionic mantle, the action theory model has been established which combined the geometric deformable model, the mechanical model and the cavity pressure model of the bionc mantle and the thermodynamic model, constitutive model of SMA. Through the analysis of the model, the action amplitude of the bionic mante and the jet thrust the bionic mantle jet propeller can produce were cauculate and the impact of the SMA wire arrangement angle on the action amplitude were investigae, and the optimal SMA wire arrangement was obtained. Then the experimental study was conducted to reseach the jet thrust performane of the bionic mantle jet propeller and the results verified the correctness of the theory.Finally, a bionic robot fish based on the bionic caudal fin propulsion and a bionic robot fish based on the bionic jet propulsion were developed respectively, and a control system can realize the self-propelled swimming was also developed. Then the swimming experiment was carried out, the results show that the bionic fish can realize the straight line swimming, the turning swimming and desired trajectory self-propelled swimming. Furthermore, the experimental results also show that the twin caudal propulsion can effectively eliminate the head swinging and improve the stability of the robot fish.更多还原