A Traveling Wave Model Guided Robotic Fish Design Using Double Slot-Crank Mechanism

In this paper, we present a novel multi-joint robotic fish design using a double-slot crank mechanism. The double slot crank (DSC) is a DC motor driven mechanism, which can convert the rotation to oscillation in two axes. This mechanism can be applied to designing a multi-joint robotic fish by using one DC motor to simulate two-joint robotic fish or cooperating with one servo motor to make a three-joint robotic fish. The slot crank enabled multi-joint design is guided by an idea traveling wave model, which can mimic the traveling wave along the fish body to optimize the propulsion efficiency as well as maneuvering capabilities. After multiple tests, the slot crank mechanism has been proven that it is an efficient propulsion mechanism for robotic fish. The DSC mechanism can achieve good performance on mimicking the real fish swimming and boosting the swimming speed. The DSC mechanism also represents good potential in imitating the real fish locomotion. It is expected to improve the power efficiency of the multi-joint robotic fish. The robotic fish with DSC enabled tail can achieve 20 cm/sec forward speed and 23.6 degree/sec turning speed with less than 8 w power consumption.