Research On The Flexible Bionic Robot Fish With Larger Amplitude And Variable Cross-section

The high speed and good mobility of natural fish has attracted wide attention of science researcher.Many scholars hope to develop an underwater propulsion system that could be comparable to natural fish by studying the swimming mechanism of fish.Underwater thrusters have an irreplaceable application value in Marine survey,water rescue,Marine archaeology,underwater entertainment,military competition,etc.The tuna becomes the subject of study to bionic workers with its fast moving speed and high efficiency.To imitate the tuna as the research target,this article put forward a way to change flexible tail's section moment of inertia,designed and developed flexible robotic fish with fast speed and good turning performance.This paper based on the analysis of the tuna fish's physiology and shape parameters,designed drive mode of robotic fish,established a three-dimensialon model of robotic fish.In order to solve the question that current bio-robot fish with flexible tail has small amplitude,a method which could lower bending stiffness by changing inertia moment was proposed.Established the physical model of flexible tail,The modal analysis of fish tail was carried out by theoretical solution and finite element theory.To solve the tail deflection of the tail,The static analysis was carried out with the software of ANSYS and Matlab.The position of the tail grooves was optimized.According to the characteristic of the bionic fish's tail movements,designed drive mode and built a three-dimensialon model of robotic fish,established hardware control system based on STC89C52 RC MCU and debugged the control system circuit,used wireless transceiver module to control the rotation Angle and rotational frequency of servo,which guarantee the changes of robotic fish tail's swing frequency and oscillation amplitude.Finally,made a prototype of biomimetic robotic fish,did a lot of experiments to test swimming performance,as a result,Variable cross-section flexible robotic fish's swimming speed is 2 times of the original robot fish,after optimizing the position of cross section,flexible robotic fish's swimming speed is 3 times as the original robot fish.the method by changing section moment of inertia can get more bigger tail's oscillation amplitude was verified,which can improve the robot fish's swimming performance.This method will offer new ideas for the future research of bionic fish and fish-like propulsor.