Bladderless swaying wire-driven Robot Shark

This paper introduces a new bio-inspired wire-driven robotic fish, called the Robot Shark. Different from the existing robotic fishes, it can sway its caudal fin to establish forward motion as well as ascending motion. First, the sway motion model is derived and computer simulations are conducted. Next, a prototype was built and a number of experiments were carried out to validate the simulation results. It is found that the maximum velocity of Robot Shark is 129.6 mm/s, or 0.22 BL/s, when the bending amplitude is 35° and the flapping frequency is 2 Hz. Moreover, its maximum body pitch angle is 17.3°.