Analysis and control of aquatic locomotion on robotic fish

• Main Author: Eric Purnama
• Other Authors: Low Kin Huat
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Mechanical engineering::Robots
• Online Access: http://hdl.handle.net/10356/60958
• Institution: Nanyang Technological University

Biomimetic approach is very profound in the search of a more effective and efficient ways of performing tasks. This includes the development of autonomous underwater vehicles (AUVs). Robotic fishes have various applications ranging from marine explorations to defense related uses. In this project, the author developed biomimetic shark, whose swimming mechanism is categorized under thunniform, one of the most efficient swimmers. All four main shark fins were applied in the robot, namely Caudal fin, Pectoral fins, and Dorsal fin. Caudal fin is the main thrust generator, while pectoral fins provide the lift required to counter the weight of the shark that is denser than the surrounding water. This locomotion system is called dynamic lift. Moreover, it has been believed that dorsal fin in shark only functions as stabilizer. However, recent study showed that it actually provides additional thrust to the fish. Therefore, this project also aims to gain clearer understanding about the shark’s dorsal fin function. Prototype was built and experiment results show that the thrust generated by the caudal fin depends on the Amplitude of undulation and the Stiffness of the caudal fin. Also, it was found that there are interactions between the two factors. In addition, experiment on the function of dorsal fin reveals that the dorsal fin lateral motion contributes significantly to the overall thrust generation of the robot. The process of designing, constructing, control algorithm development, and testing are presented in this report.