Meeting Abstract
Batoid fish such as manta and cownose rays outperform man-made autonomous underwater vehicles in maneuverability and efficiency over a wide range of speed. These capabilities can be attributed to their extremely flexible fins, which may flap and pitch in a way that optimizes the overall performance during swimming. In this study, we developed and tested the MantaBot, which was inspired by biological design criteria in batoid: flattened rigid body and flexible actuators. The MantaBot body was rendered from a computer tomography scanning image of a cownose ray. The flexible fins were made of elastomer in an airfoil cross-section shape. The fins were driven by active tensegrity structures. An additional rigid fin was attached to the rear of the body for pitch control. The vehicle was powered by a Li-ion battery pack and controlled by an Arduino microcontroller. A pressure sensor and a MEMS gyroscope/accelerometer device were equipped in the system for depth feedback control and navigation. The experiments were conducted in a water tank where the Mantabot was attached to a rail for rectilinear swimming. Optimal operation conditions (fin flapping amplitude and frequency) were determined for fastest swimming by surveying a wide range of parameters. Free swimming tests were done in a swimming pool. Our results show the MantaBot can swim faster than one body length per second and cruise about 7 km per charge. These results demonstrate that enhanced swimming performance can be achieved through bio-inspired designs based on rays.
