Dynamics Of Piezoelectric Micro-robotic Fish With Double Caudal Fins

Bionic micro-robots have received extensive attention due to their strong robustness,high flexibility,and diverse motion modes.Among them,the tail-fin type micro-robotic fish bionic can move flexibly in a limited space due to its small size.At the same time,pipeline inspection and water quality inspection can be completed in narrow waters.In addition,due to its camouflage nature,the tail-fin fish bionic robot can also complete security tasks such as military detection.The micro-robotic fish driven by smart materials has significant advantages over the traditional motor and piston driven robotic fish.They are particularly efficient and compact,but often have problems such as low thrust,high driving voltage,and low energy density.In addition,the high density of traditional metal,plastic and other materials,coupled with the large volume of traditional gears,pistons and other transmission mechanisms,makes it difficult to produce small,light,and simple structured micro robotic fish,which is not conducive to improving its swimming speed.This subject proposes a dual-tail fin type micro robotic fish driven by two dual-crystal piezoelectric cantilever beams.The dynamic and kinematic models of the micro-robotic fish are established.The variation laws of its normalized thrust,normalized displacement and normalized velocity are qualitatively calculated.The analysis shows that the thrust and swimming velocity can be improved by applying the electric signal with the same resonance frequency and increasing the driving voltage.After that,the thrust,displacement and velocity of the micro-robotic fish are tested.The test data refine the theoretical analysis value,which can be used to design and analyze various piezoelectric micro-robotic fish.The micro-robotic fish has a maximum thrust of 243 ?N,and a maximum average swimming speed of about 0.75BL/s(4.5 cm/s)at 130 V,4 Hz.After that,the turning performance of the micro-robotic fish was tested.The minimum turning radius is 1.4 cm,under 80 V,1 Hz.Finally,the energy consumption of the micro-robotic fish is tested.The maximum energy consumption P of the micro-robotic fish is about 0.645 m W,the maximum output power is about 0.0109 m W,and the total efficiency ? is about 1.69%.The efficiency of this micro-robotic fish is significantly higher than that of other similar micro-robotic fish.