Hydrodynamic Simulation of Five Degree of Freedom Underwater Manipulator

Accurate hydrodynamic and dynamic modeling of underwater robotic arms is essential for their stable operation in marine environments. Traditional methods, relying on empirical coefficients, often fail to capture the unique characteristics of specific robotic systems. This paper presents a five-degree-of-freedom underwater robotic arm and develops a detailed hydrodynamic model. Using Ansys-Fluent, the water resistance and added mass force coefficients for the arm's linkage and joints are calculated in various motion directions. Morison's equation is used to link hydrodynamic forces to motion parameters, resulting in a comprehensive dynamic model. Validation shows that the proposed method provides a more accurate hydrodynamic model, improving fitting accuracy by approximately 43987 times compared to the empirical method, as measured by the residual sum of squares. This work lays the foundation for future fluid-structure coupling simulations and control algorithms.