Development of Fish type Robot based on the Analysis of Swimming Motion of Bluefin Tuna -Experimental Discussion-

Abstract

The swimming motion of Tuna type fishes has excellent ability in its speed and efficiency. On the other hand, some studies on the most efficient swimming motion have been reported using numerical analysis of a two-point hinge mechanism model. However, since most conventional fish robots hold their caudal fin in a spring, the caudal fin works only passively and can not confirm theoretical results in an experimental way. Therefore, we developed a fish type robot that combines caudal fin angle actuating mechanism and tail oscillating mechanism. Using this robot, we experimentally investigated the change in swimming speed due to the difference in swimming motion.

Route Estimation Toward Autonomous Swimming of Robotic Fish

“…Further, the velocities, 𝑣𝑣 𝑥𝑥 and 𝑣𝑣 𝑦𝑦 , are calculated in the global coordinates using the yaw angle 𝜓𝜓, the velocity 𝒗𝒗, and the initial head angle 𝜃𝜃 𝐷𝐷 from Equation (4).…”

“…When swimming forward, the reference plane is defined at the center of the body and is biased to the left or right when turning. In this way, actuating the two axes independently provides more natural undulation and higher turning capability than a passive movement of spring-coupled tail fin against water resistance [4].…”

“…Although UUVs can potentially contribute to underwater exploration operations, they are insufficient for performing tasks in confined environments. In particular, screw-mounted UUVs have an impact on the surrounding environment such as engulfing seaweed and rolling up sand from the seafloor [4], and marine organisms are cautious around UUVs, making it difficult to study their natural ecosystem.…”