Calibration of 3-d.o.f. Translational Parallel Manipulators Using Leg Observations

TL;DR

This paper introduces a low-cost, observation-based calibration method for 3-DOF parallel manipulators, improving geometric accuracy by measuring leg parallelism deviations during motion.

Contribution

It presents a novel calibration approach using simple measurements of leg parallelism, enabling effective parameter estimation without expensive equipment.

Findings

Calibration accuracy improved through experimental validation.

The method effectively estimates joint offsets and leg lengths.

Low-cost and practical for real-world applications.

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.