Toward a Transform Method From Lighthill Fish Swimming Model to Biomimetic Robot Fish

How to build a biomimetic robot fish has always been a divergent question. Most of the existing robot fishes suffer structural complexity and propulsive inefficiency. In this paper, we proposed a method that transfers the natural actuation properties of fish to the biomimetic robot counterpart. The natural properties were analyzed based on the Lighthill fish swimming model and the actuation function of fish muscles. The analyses shown that the compliant part is feasible in fish propulsion, which means nonactuated/compliant part is also feasible to achieve an effective propulsion on robot fish, and an example of this type of robot fish and its general kinematic model are presented. This transform method not only can demonstrate the actuation features of fish, but also can reduce the motors in building robot fish. The method has also been extended to apply on different swimming modes, offering a general guidance to build efficient biomimetic robot fishes with fewer motors.