Calibration of quasi-isotropic parallel kinematic Machines: Orthoglide

TL;DR

This paper introduces a low-cost, practical calibration method for Orthoglide parallel kinematic machines, improving accuracy by measuring leg parallelism deviations during specific motions.

Contribution

It presents a novel, cost-effective calibration approach based on simple measurements of leg parallelism to estimate joint offsets and leg lengths.

Findings

Calibration improves manipulator accuracy.

Method is validated through experimental results.

Uses standard comparator indicators for measurements.

Abstract

The paper proposes a novel approach for the geometrical model calibration of quasi-isotropic parallel kinematic mechanisms of the Orthoglide family. It is based on the observations of the manipulator leg parallelism during motions between the specific test postures and employs a low-cost measuring system composed of standard comparator indicators attached to the universal magnetic stands. They are sequentially used for measuring the deviation of the relevant leg location while the manipulator moves the TCP along the Cartesian axes. Using the measured differences, the developed algorithm estimates the joint offsets and the leg lengths that are treated as the most essential parameters. Validity of the proposed calibration technique is confirmed by the experimental results.