| Bionic robot fish a kind of underwater vehicle has great application value,especially in marine observation,underwater exploration,and military and other applications,which is very extensive and it has become a research hotspot of underwater robot.The carangidae fishes has excellent ability of underwater motion by means of body/tail fin propulsion(body and/or caudal / fin,BCF)and it has very high research value.But the traditional robot fish with a structure of multi-mechanical joint series parallel has a low efficiency,and the more mechanical joint the more energy transmission it will loss,what's more,the mechanical design and control algorithm are also more complex.The flexible body has an infinite number of degrees of freedom,and the input energy through elastic and inertial storage by viscous dissipation,so if we can design a flexible propulsion complex movement of fish reproduction device,then the device compared to multi joint series parallel mechanism will has more advantages.This subject based on the National Natural Science Foundation "Research on bionic carangidae fish propulsion mechanism of the project" to have a research on the Flexible Biomimetic Fish.This study intends to improve the flexibility of bionic fish by means of flexible coupling system of the propulsion performance,and explore the parameters to promote the effect of the flexible fin speed and propulsive efficiency comprehensive optimization in parameters,so as to ensure the high efficiency under the premise of promoting the swimming speed set.The main contents of this project are as follows:(1)Research on the mechanism of carangidae fishes,explore and analyze the effect of fish in different parts of the structure and speed of the propulsive efficiency of fish propulsion,and lay the foundation to study the effect of caudal fin in the process of advancing the design of bionic robot fish body structure.(2)Taking the carangidae carp as the bionic object,with the actual reference measurement for carp fish shape parameters,and according to the design parameters of the fish body structure of a single joint swing body / tail.The use of rapid prototyping 3D model technology to print the fish body structure,the fish body before the 2/3 part is a rigid structure,after 1/3 using silica gel is designed as a flexible structure,the caudal fin set for flexible and rigid hybrid structure,complete the design of fish body structure.(3)According to the movement characteristics of bionic robot fish,using magnets and hollow coil design structure and control design of fin propulsion,the tail beat output hardware circuit two PWM signals using X281 x DSP as main control chip,the swing motion simulation of tail fin of carp.(4)With the design of the X281 x DSP chip control software based on C program,to achieve the output of the two independent PWM wave,and in accordance with certain frequency switching or modify the cycle of PWM wave and duty ratio,and then develop the PC program Lab VIEW to realize data transmission between PC and robotic fish system.(5)According to the requirement of data transmission speed and data volume,the PC program based on Lab VIEW is developed by using VISA serial port module to realize the data transmission between PC and robot fish system.(6)Build a fish body image processing platform based on propulsion performance test,and developed an improved image target tracking accuracy of robot fish in the underwater target motion tracking algorithm,and then through the camera calibration calculation of robot fish swimming speed.Finally,the relationship curve between the swimming speed of fish and the ratio of the tail fin,the swing frequency and the power consumption of the system is studied.In summary,this project studies the principle of carangidae fishes in carangidae carp as the bionic object,to improve propulsive efficiency for the purpose of design of the bionic robot fish is a flexible body tail structure.By exploring the robot fish propulsion speed and caudal aspect ratio,caudal oscillation frequency,modal distribution curve,optimized to achieve a fish tail to promote efficient parameter set,beneficial exploration of theoretical basis and practical aspects for the development of high speed,high efficiency,high maneuverability of bionic propeller swing.Experiments show that the tail beat frequency is the biggest factor affecting the fish propulsive efficiency,improve the oscillation frequency will increase the speed,but in certain frequency will reduce the propulsive efficiency and increase the power consumption;in certain power input,the caudal fin aspect ratio larger fish machine push with greater speed,and aspect ratio the greater the more caudal fin shape tends to crescent shape;the modal also affect the machine fish caudal advance speed,modal distribution right but also conducive to enhancing the robot fish propulsion efficiency. |
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