New Method and Portable Measurement Device for the Calibration of Industrial Robots

Area of Science:

• Robotics
• Metrology
• Mechanical Engineering

Background:

• Industrial robot calibration is crucial for precision tasks.
• Existing methods can be costly or complex.
• Accurate calibration enhances robot performance and reduces errors.

Purpose of the Study:

• To present an automated, low-cost calibration method for industrial robots.
• To introduce a novel wireless 3D measuring device (TriCal) and a portable 3D ball artifact.
• To validate the effectiveness of the TriCal system against traditional methods.

Main Methods:

• Developed TriCal: a wireless 3D device with three digital indicators for Tool Center Point (TCP) detection.
• Utilized a portable 3D ball artifact with known ball positions.
• Automated measurement procedure involving robot TCP alignment with artifact balls.
• Employed least-squares method for identifying kinematic and joint stiffness parameters.
• Validated accuracy using a laser tracker for comparison.

Main Results:

• The TriCal system achieved high accuracy in robot calibration.
• Maximum position errors were 0.624 mm, with mean position errors of 0.326 mm.
• The TriCal method demonstrated comparable accuracy improvements to laser tracker calibration.

Conclusions:

• The TriCal system offers an efficient and accurate solution for industrial robot calibration.
• This novel approach provides a cost-effective alternative to existing calibration techniques.
• Automated calibration using TriCal significantly enhances robot precision and reliability.