Underwater Dynamic Modeling for a Cable-Driven Soft Robot Arm

Soft robotics has attracted great attention because of its potential to overcome safety issues and produce a more harmonious cooperative environment for human beings and robots. One of the main challenges hindering its wider application to the daily routine is the dynamic modeling of its compliant mechanisms. In this paper, to further investigate the soft robot arm's performance and extend the utilization in water or other dense and viscous mediums, the dynamic model based on Kane's theory is proposed. This model takes complicated hydrodynamics into account with reasonable simplification, considering the physical conditions. Compared with the previous work, we adopt the Column friction model to compensate for the actuation force's loss in the transmission process. The proposed dynamic model is validated by comparing the theoretical results of both the dynamic responses and steady-state poses with the experimental results under different conditions. Given the modification method for the computed dynamic equation, the presented dynamics can adapt to variable environments and serve as the platform for the controller design for a soft robot working in a complex environment.