一种新型尾鳍推进的机器鱼设计与实验研究

发布时间：2018-10-11 17:04

【摘要】：与传统的水下推进器相比,仿生机器鱼具有推进效率高、机动性好和对环境扰动小等优点。因此,仿生机器鱼的设计和研究成为水下机器人领域的一个重要课题。研究表明,对于身体-尾鳍推进(简称BCF)运动模式的机器鱼,推进机构的工作效率是影响机器鱼游速的一个重要因素;具有二维运动空间的尾鳍推进器能极大地精简机器鱼的机械结构和运动控制。本文设计了一款基于新型二自由度尾鳍推进机构的仿生机器鱼,避免了推进机构中电机频繁正反转导致的低传动效率问题,并且只通过尾鳍就实现了机器鱼的直线巡游、转弯、上浮和下潜四种基本运动。机器鱼的水下实验结果表明,机器鱼具有良好的游速和机动性能,可为机器鱼的推进机构设计提供一种新的参考。主要研究内容如下:(1)设计了一种新型的二自由度尾鳍推进机构,并完成了机器鱼的系统设计。介绍了在机器鱼的设计过程中需要解决的主要问题和系统构成,在比较分析现有推进机构的基础上,提出了一种二自由度尾鳍推进机构的设计方案,并给出了具体的结构设计。确定了使用大容量锂电池和无刷直流电机作为机器鱼的动力单元,解决了机器鱼的无线通讯设计和硬件设备方案设计。对机器鱼的密封方案进行了优化设计,借助SolidWorks工具对机器鱼的配重进行了评估。最终,完成了二自由度尾鳍推进仿生机器鱼的原理样机设计。(2)建立了二自由度尾鳍推进机构的运动学方程并进行了虚拟样机仿真分析。介绍了该新型二自由度尾鳍推进机构的运动原理,以双斜面转块和万向节的运动一致性作为解决推进机构运动学方程的出发点,推导了推进机构的运动学方程,给出了运动学正、逆解。提出了推进机构的电机同速同向运动和同速反向运动的两种运动模式,以及速度和位置的两种控制模式。在Adams中对机器鱼虚拟样机模型的直线游动、转弯、上浮和下潜方式进行了运动学仿真,给出了尾鳍摆角在相应的电机输入函数下的变化曲线,验证了该新型二自由度尾鳍推进机构用于机器鱼的可行性。(3)开展了机器鱼的游动测试和实验结果分析。根据运动学仿真的结果,建立了五种游动姿态下的控制策略,给出了相应的电机控制参数变化表,并在Visual Studio环境下编写了控制程序。实验前完成了对各模块的调试、密封性检验和配重修正。利用无人机航拍的方式在户外水塘中进行了直线游动和转弯游动实验,通过对获取的视频进行处理得到机器鱼位置坐标的游动实验数据。实验结果表明,机器鱼的游速约为0.69m/s,最小转弯半径约为0.23m(0.16BL)。
[Abstract]:Compared with the traditional underwater propeller, the bionic robot fish has the advantages of high propulsion efficiency, good maneuverability and low disturbance to the environment. Therefore, the design and research of bionic robot fish has become an important subject in the field of underwater vehicle. The research shows that the working efficiency of the propulsion mechanism is an important factor to affect the swimming speed of the robot fish with body-caudal fin propulsion (BCF) motion mode. The caudal propeller with two-dimensional motion space can greatly simplify the mechanical structure and motion control of robot fish. In this paper, a bionic robot fish based on a new two-degree-of-freedom tail fin propulsion mechanism is designed, which avoids the problem of low transmission efficiency caused by the frequent forward and backward rotation of the motor in the propulsion mechanism, and realizes the straight line cruise and turning of the robot fish only through the caudal fin. Floating and diving four basic sports. The underwater experiment results of the robot fish show that the robot fish has good swimming speed and maneuverability, which can provide a new reference for the design of the propulsion mechanism of the robot fish. The main contents are as follows: (1) A new 2-DOF caudal fin propulsion mechanism is designed, and the system design of robot fish is completed. This paper introduces the main problems and system structure in the design of robot fish. On the basis of comparing and analyzing the existing propelling mechanism, a design scheme of two-degree-of-freedom caudal fin propulsion mechanism is put forward, and the concrete structure design is given. The large capacity lithium battery and brushless DC motor are used as the power unit of the robot fish. The wireless communication design and hardware design of the robot fish are solved. The sealing scheme of robot fish was optimized and the weight of robot fish was evaluated by SolidWorks tool. Finally, the principle prototype design of two-degree-of-freedom caudal fin propulsion bionic robot fish is completed. (2) the kinematics equation of two-degree-of-freedom caudal fin propulsion mechanism is established and the virtual prototype simulation analysis is carried out. This paper introduces the motion principle of the new two-degree-of-freedom caudal fin propulsive mechanism. The kinematics equation of the propeller mechanism is derived by using the kinematic consistency of the double inclined plane turning block and the universal joint as the starting point to solve the kinematics equation of the propulsion mechanism. The forward and inverse kinematics solutions are given. In this paper, two motion modes of the motor in the same speed and the reverse motion at the same speed, as well as the two control modes of the speed and the position of the propulsion mechanism are proposed. In Adams, the kinematics simulation of the straight line swimming, turning, floating and diving mode of robot fish virtual prototype model is carried out, and the variation curve of tail fin swing angle under the corresponding motor input function is given. The feasibility of the new two-degree-of-freedom caudal fin propulsion mechanism for robot fish was verified. (3) the swimming test and experimental results of the robot fish were carried out. According to the results of kinematics simulation, five control strategies under swimming attitude are established, and the corresponding control parameter table is given, and the control program is written in Visual Studio environment. Before the experiment, the debugging, sealing test and counterweight correction of each module were completed. In this paper, the swimming experiment of straight line and turn was carried out in the outdoor pond by aerial capture of UAV. The swimming experiment data of the position coordinates of the robot fish were obtained by processing the obtained video. The experimental results show that the speed of swimming is about 0.69 m / s and the minimum turning radius is about 0.23 m (0.16BL).
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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