Development of modular and reconfigurable biomimetic robotic fish with undulating fin

Different versions of biomimetic robotic fish mimicking undulating fins of black ghost knifefish have been designed and developed. To mimic the actual flexible fin of real fish, an optimized fin-like propulsion mechanism is modelled with a series of connecting linkages for enhancing its propulsive performance. Motion studies for optimizing the undulating fins design have been conducted. Workspace and locomotion of the fin mechanism are derived and the parametric study of the locomotion is presented. With these studies, an optimal design providing the best workspace, which can drive the highest possible amplitude, have been developed. The manoeuvrability and buoyancy control can be achieved by the integration of mechatronics design of a buoyancy module with the undulating fin. The design philosophy of modularity was incorporated into the design of the fish. Hence, the modularity of the prototypes not only provides versatility for the robot system and also facilitates in the maintenance and future development of fish with undulating fins/body, as new modules can be added to replace the existing modules easily. By reconfiguring the components of NKF-II, other version of robotic fish with undulating fins/body is derived. This evolution of the undulating fins is also discussed.