Dynamic Model and Analysis of Soft Manipulator Facing Underwater Complex Environment

A soft manipulator possesses high flexibility, safe human-machine interaction and environmental adaptability. It can be mounted on the ROV to conduct underwater sampling, grasping and operation tasks. Therefore, it is widely used in marine scientific investigation, marine engineering, rescue and salvage engineering. In order to further improve the accuracy of simulating and predicting the underwater motion of the soft manipulator, this paper proposes a Cosserat-rod theoretical dynamic model based on time-discrete solution, which fully considers the influence of external forces such as gravity, buoyancy, additional mass force and resistance (linear term and nonlinear term) on the motion of the manipulator in the water environment. In addition, the six-dimensional strain state of bending, torsion, stretching and shearing of the robot manipulator in the x-direction, y-direction and z-direction is described in detail to simulate its accurate movement in the complex underwater environment. The predictability and accuracy of the dynamic model provide a certain theoretical reference for the underwater application of the soft manipualtor.