Changing Assembly Modes without Passing Parallel Singularities in Non-Cuspidal 3-R\underline{P}R Planar Parallel Robots

TL;DR

This paper shows that certain 3-DOF planar parallel robots can switch assembly modes without encountering singularities, challenging traditional definitions and understanding of parallel singularities.

Contribution

It introduces a theoretical framework demonstrating assembly mode changes without passing through parallel singularities in non-cuspidal 3-RPR robots.

Findings

Assembly mode changes are possible without passing through singularities.

Theoretical results question the traditional definition of parallel singularities.

Highlights potential for more flexible robot reconfiguration.

Abstract

This paper demonstrates that any general 3-DOF three-legged planar parallel robot with extensible legs can change assembly modes without passing through parallel singularities (configurations where the mobile platform loses its stiffness). While the results are purely theoretical, this paper questions the very definition of parallel singularities.