The Design and Analysis of UPRUPUUR Vector Propulsion Mechanism In recent years, many countries have gradually turned their development judgments to marine development, put forward the goal of building a powerful marine development country, underwater robots have become the hotspot of current development. The propulsion mechanism of underwater vehicle is the key technology that restricts the development of robot. In order to meet the needs of high efficiency propulsion of underwater vehicle, the model of UPRUPUUR vector propulsion mechanism is designed. According to the principle of parallel mechanism, Calculating the degree of freedom of the mechanism. Then the inverse solution of position is derived from the position relation. The position workspace simulation of the mechanism is carried out, and the simulation results are compared with the theoretical analysis results, which proves the correctness of the design and theoretical derivation. The parallel mechanism can achieve multiple directions attitude rotations, which provides a reliable theoretical basis for underwater vehicle.

Design of a Robotic Fish Based on a Passive Flexible Mechanism In recent years, along with the rapid development of manufacturing, control, sensing and other technologies, biomimetic robotic fish has played an increasingly important role in marine exploration, underwater rescue, water quality monitoring and other fields. This paper designed a robotic fish based on a passive flexible mechanism to realize the fishlike propulsion function. The motion simulation of the designed transmission mechanism was carried out to get the actual curve of the structure. Through the analysis of the force of the fishtail, the preliminary selection scheme of the elastic joints based on the passive flexible mechanism was obtained. Finally, this paper built a robotic fish based on a passive flexible mechanism, which could achieve the motion frequency adjustable from 0.5 to 9 Hz, and the maximum swimming speed reaching 1.05 BLs (BL, body length). This design scheme provided a new reference for the design of the biomimetic robotic fish and had certain practical significance.