Design and depth control of bionic mantis shrimp underwater robot with miniaturized low-cost sinking and floating system

Bionic underwater robots have broad application prospects in ocean exploration, environmental monitoring and other fields, but the cost and miniaturization of their depth control system limit the practical application. Based on the motion mechanism of mantis shrimp, this paper designs a bionic mantis shrimp robot, proposes a depth control method of bionic mantis shrimp underwater robot based on a miniaturized low-cost subsidence and floating system, and designs a lightweight subsidence and floating structure combined with peristaltic pump drive and variable volume cavity. The hybrid control algorithm of adaptive sliding mode control and extended observer is used in the system. Through simulation and experimental verification, the proposed method can make the bionic mantis shrimp robot realize the depth control of the average depth error less than 5 cm under different water depth conditions and has high robustness and adaptability. This study provides a new idea for the design of depth determination system of underwater bionic robots. • A slender bionic mantis shrimp robot featuring rigid-flexible coupling design for narrow underwater environments. • Lightweight sinking/floating structure with peristaltic pump drive and variable cavity for bionic mantis shrimp robot. • Real-time disturbance estimation based depth control for the bionic mantis shrimp robot.