Vibration Analysis of a Soft Hydrodynamic Manipulator

Abstract Soft robotic manipulators, driven by fluidic actuation, surpass rigid counterparts with increased degrees of freedom, enabling exploration of intricate workspaces. Despite potential vibrations from power fluctuations, these can be mitigated using damping fluids. This paper focuses on experimentally analyzing the vibrations of a soft hydrodynamic manipulator. To this end, a soft manipulator was fabricated, and a corresponding test setup was devised. Employing three distinct test fluids water, engine oil, and mustard oil with large viscosity variations, the research characterized vibrations through the ripple factor. This metric was computed based on temporal shifts in linear and angular displacements across various planes. Notably, the findings indicate that, owing to its lower viscosity, water exhibits maximum deflection at a higher Reynolds number (Re ≥ 100) compared to engine oil (Re= 9.3) and mustard oil (Re= 8.31). Additionally, the ripple factors suggest that, for water, vibration is higher those observed in the other two test fluids.