Kinematic Calibration of the Orthoglide-Type Mechanisms

TL;DR

This paper introduces a low-cost calibration method for Orthoglide-type mechanisms that uses simple comparator indicators to measure leg deviations during motion, enabling effective joint offset estimation.

Contribution

It presents a novel, cost-effective calibration approach based on leg parallelism observations and a new algorithm for joint offset estimation in Orthoglide mechanisms.

Findings

Calibration accuracy is validated through experiments.

The method effectively estimates joint offsets.

Measurement sensitivity analysis supports the approach.

Abstract

The paper proposes a novel calibration approach for the Orthoglide-type mechanisms based on observations of the manipulator leg parallelism during motions between the prespecified test postures. It 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 that are treated as the most essential parameters to be adjusted. The sensitivity of the measurement methods and the calibration accuracy are also studied. Experimental results are presented that demonstrate validity of the proposed calibration technique.