Introduction of a Flexible Adaptive AUVCapture Device Based on bioinspired hydraulic Soft Robot To capture the noncooperative and crossscale underwater objects, an underwater soft bionic robot is proposed according to task function analysis and bionics inspiration. The device was mainly composed of a soft bionic arm and a soft body. It has the abilities of longdistance reachability, end pose adjustment, crossscale capture, target measurement and recognition. The soft bionic arm is driven by water filling, which has the characteristics of light weight and large shrinkage ratio. It consists of several serially arranged modular soft actuators with diverse functions which can be designed for deepsea object retrieving. The soft modules are connected by quickshift joints, which make it possible to adjust the arm configuration specific to the task requirement in situ. The method to test the performance of each functional module is also introduced.

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.