Abstract: Thunniform swimmers (tuna) have a swinging narrow sequence stalk and a moon-shaped tail fin, which performs poorly at slow speed, higher acceleration and turning maneuverability. In most cases, faster speed and higher maneuverability are mutually rejection for most marine creatures and their robotic opponents. This paper presents a novel hybrid tuna-like swimming robot for aquaculture water quality monitoring, which interleaves faster speed and higher maneuverability. The robotic prototype emphasizes on streamlining and enhanced maneuverability mechanism designs in conjunction with a narrow caudal propeller to the tail. The innovative design endows the robot to easily execute the multi-mode swimming gait, including forward swimming, turning, diving/surfacing. The capabilities of our robot are validated through a series of indoor swimming pool and field breeding ponds. The robotic fish can achieve a maximum speed up to about 1.16 m/s and a minimum turning radius less than 0.46 Body Lengths (BL) and its maximum turning speed can reach 78.6 °°/s. Due to its high speed, maneuverability and relatively small size, the robotic fish shed light on intelligent monitoring in complex aquatic environments.

Key words:  , Hybrid-drive biomimetic robot fish , · Water quality monitoring , · Multimodal swimming gait