Development of a Novel Underactuated Robotic Fish with Magnetic Transmission System

In this study, a robotic fish inspired to carangiform swimmers has been developed. The artifact presents new transmission system that employs the magnetic field interaction of permanent magnets ensure waterproofness and prevention from any overload for structure actuating motor. This mechanism converts rotary motion motor into oscillatory motion. Such an oscillating system, along with wire-driven tail, generates required traveling wave in fish. complete free swimming fish, measuring 179 mm length mass only 77 g, was able maintain correct posture neutral buoyancy water. Multiple experiments were conducted test performance. It could swim maximal speed 0.73 body lengths per second (0.13 m/s) at tail beat frequency 3.25 Hz electric power consumption 0.67 W. Furthermore, touched upper bound efficient range, expressed by dimensionless Strouhal number: 0.43 1.75 frequency. lowest energy travel 1 meter 4.73 Joules final prototype. Future works will focus on endowing robot navigation autonomy, testing its potential real-world applications such as environmental monitoring animal–robot interaction.