Dynamics for biomimetic continuum arms: A modal approach

This paper presents an improved 3D dynamic model based on mode shape functions for biomimetic continuum robotic arms intended for underwater operation. It is an extension to the dynamic model proposed in the author´s previous work to incorporate angular moments and hydrodynamic forces such as buoyancy, lift, and drag. The proposed model is based on an accurate kinematic model and gives an enhanced insight into practical mechanics. Also, it can be generalized for any variable length continuum arm to include external forces. A feedback control structure in the joint space is also implemented for increased performance of the continuum arm. Numerical results demonstrate underwater effects for spatial bending and pure elongations/contractions. The model carefully accounts for mechanical constraints in the joint space to yield physically accurate results.