Bio-harmonized Dynamic Model of a Biology Inspired Carangiform Robotic Fish Underwater Vehicle ?

This paper presents a novel dynamic model of a bio-inspired robotic fish underwater vehicle by unifying conventional rigid body dynamics and bio-fluid-dynamics of a carangiform fish swimming given by Lighthill’s (LH) slender body theory. It proposes an inclusive mathematical design for better control and energy efficient path travel for the robotic fish. The system is modeled as an 2-link robot manipulator (caudal tail) with a mobile base (head). Lighthill caudal-tail reactive forces and moments are shown to contribute towards thrust generation and yaw balance. These LH reactive forces are shown to generate the inertial added mass during the robotic fish locomotion. This forward thrust drives the robotic fish head represented by a unified non-linear equation of motion in earth fixed frame. Using the proposed dynamic model an open-loop (manual) operating region for the identified kinematic parameter tail beat frequency (TBF) is established. Obtained Kinematic results also resemble with real fish kinematic results. The objective is to mimic the propulsion technique of the carangiform swimming style and to show the fish behavior navigating efficiently over large distances at impressive speeds and its exceptional character in fluid environment.