Locomotion Consideration and Implementation of Robotic Fish with Modular Undulating Fins: Analysis and Experimental Study

This paper presents an environment-friendly robotic system mimicking undulating fins of fish. To mimic the actual flexible fin of a real fish, we model a fin-like mechanism with a series of connecting linkages and attached it to the robotic fish. By virtue of a specially designed strip, each link is able to turn and slide with respect to the adjacent link. The driving linkages are used to form a mechanical fin consisting of several fin segments, which are able to produce undulations, similar to those produced by the actual fins. Owing to the modular design and the flexible structure of the mechanical fin, we were able to construct biomimetic robot fish with various swimming modes by fin undulations. Some qualitative and workspace observations by experiments with the robotic fish are shown and discussed