Design of a Spherical Wrist with Parallel Architecture: Application to Vertebrae of an Eel Robot

TL;DR

This paper presents the design and kinematic analysis of a spherical parallel wrist mechanism tailored for an eel robot used in inspecting submerged pipes, emphasizing compactness, symmetry, and shape adaptability.

Contribution

It introduces a novel spherical wrist design with specific constraints for underwater inspection robots, including kinematic characterization and application-specific features.

Findings

Identified singular and isotropic configurations of the mechanism

Designed a compact, symmetric mechanism suitable for eel robot application

Ensured the mechanism can fill elliptical pipe sections

Abstract

The design of a spherical wrist with parallel architecture is the object of this article. This study is part of a larger project, which aims to design and to build an eel robot for inspection of immersed piping. The kinematic analysis of the mechanism is presented first to characterize the singular configurations as well as the isotropic configurations. We add the design constraints related to the application, such as (i) the compactness of the mechanism, (ii) the symmetry of the elements in order to ensure static and dynamic balance and (iii) the possibility of the mechanism to fill the elliptic form of the ell sections.