A design oriented study for 3R Orthogonal Manipulators With Geometric Simplifications

TL;DR

This paper introduces a method to compute the largest Regular Dextrous Workspace (RDW) for certain 3R orthogonal manipulators with zero DH parameters, and proposes a new performance index to optimize manipulator design.

Contribution

It presents a novel approach for calculating RDW and a new performance index, aiding in the design of more effective manipulator geometries.

Findings

RDW can be effectively calculated for manipulators with zero DH parameters.

A new performance index based on RDW helps compare manipulator architectures.

Identified parameter domains for optimal manipulator designs.

Abstract

This paper proposes a method to calculate the largest Regular Dextrous Workspace (RDW) of some types of three-revolute orthogonal manipulators that have at least one of their DH parameters equal to zero. Then a new performance index based on the RDW is introduced, the isocontours of this index are plotted in the parameter space of the interesting types of manipulators and finally an inspection of the domains of the parameter spaces is conducted in order to identify the better manipulator architectures. The RDW is a part of the workspace whose shape is regular (cube, cylinder) and the performances (conditioning index) are bounded inside. The groups of 3R orthogonal manipulators studied have interesting kinematic properties such as, a well-connected workspace that is fully reachable with four inverse kinematic solutions and that does not contain any void. This study is of high interest for the design of alternative manipulator geometries.