Modular design and motion control of reconfigurable robotic fish

This paper presents a module-based approach to the design of robotic fish. A remotely-controlled, free-swimming robotic fish is constructed with a head module, a pair of pectoral fin modules and two tail modules. Propulsion and maneuvering of the robotic fish can be achieved either by explicit joint angle control of the tail modules or with combined pitching and heaving motion of the pectoral fins. A unified equation that governs the motion of the robotic fish is derived, based on which several typical swimming behaviors are designed. Experiments are conducted to evaluate the swimming performance of the robotic fish.