Uniqueness domains and non singular assembly mode changing trajectories

TL;DR

This paper explores the concept of uniqueness domains in parallel robots to understand non-singular assembly mode changing trajectories, emphasizing the role of cusp points in joint space for such motions.

Contribution

It introduces an approach based on uniqueness domains to explain how non-singular assembly mode changes occur in parallel robots.

Findings

Uniqueness domains help explain non-singular assembly mode changes.

Cusp points in joint space are crucial for enabling these trajectories.

The approach clarifies the relationship between singularity-free regions and assembly mode transitions.

Abstract

Parallel robots admit generally several solutions to the direct kinematics problem. The aspects are associated with the maximal singularity free domains without any singular configurations. Inside these regions, some trajectories are possible between two solutions of the direct kinematic problem without meeting any type of singularity: non-singular assembly mode trajectories. An established condition for such trajectories is to have cusp points inside the joint space that must be encircled. This paper presents an approach based on the notion of uniqueness domains to explain this behaviour.