Design and Initial Testing of a Single-Motor-Driven Spatial Pectoral Fin Mechanism

This paper aims to study drag based labriform mode of locomotion in fishes and attempts to design and develop a prototype performing pectoral fin motions. The methodology involves pectoral fin mechanism concept generation, design, development, and performance analysis. For labriform mode drag based propulsion, the initial design makes use of a rotating disk on which a planet gear rotates around a fixed sun gear, conjunction with universal and spherical joints. The model is able to achieve pectoral fin motions rowing, flapping and feathering in an integrated manner, with a single motor. The unique feature of this prototype which makes it attractive from earlier designs is its capability to produce desired velocity by making use of a single power source. Initial studies carried out on the prototype´s performance with respect to its potential to emulate actual pectoral fin movement gives promising results. It shows that the pectoral fin model can be incorporated into an autonomous underwater vehicle (AUV).